981 + super unleaded? - Page 3 - Boxster/Cayman - PistonHeads UK

Hi all - not that many chances to fill up the 2015 Boxster S since I bought it in December, but so far I’ve stuck to super unleaded. That’s what’s in the book and filler cap. Bypassing any additional performance benefits (I wouldn’t notice going by past cars), do many owners bother stick to super or just default to normal? Thanks!

If you want to be able to use the full performance potential of the car you need to run it on super. If you're not bothered, the other stuff will work just fine.

I chuck Super in the 981 2.7 we have. Porsche seemed to recommend it and probably runs a bit cleaner. It's a weekend toy though so it's an easier choice to make than if hacking up and down motorways at under 3k revs.

Not just any Super. Shell first choice. Only BP or Texaco otherwise. Don't touch supermarket stuff. Learnt from experience they are NOT all the same.

DJMC said: Not just any Super. Shell first choice. Only BP or Texaco otherwise. Don't touch supermarket stuff. Learnt from experience they are NOT all the same. I'd be interested to know what your experience was if you have time. I've owned my Gen 1 Cayman S for 11 years now (it's a 14 yr old car) and yes, it's the one the internet hates for fear of the engine exploding if you so much as look at it! Only used as a 2nd car so relatively low mileage. Never been tracked but does get a decent drive when I do use it! Only ever put Tesco super unleaded in it as it's nearby and it goes ok for me. Am I missing something or is this a whole new debating area?

Lonely said: DJMC said: Not just any Super. Shell first choice. Only BP or Texaco otherwise. Don't touch supermarket stuff. Learnt from experience they are NOT all the same. I'd be interested to know what your experience was if you have time. I've owned my Gen 1 Cayman S for 11 years now (it's a 14 yr old car) and yes, it's the one the internet hates for fear of the engine exploding if you so much as look at it! Only used as a 2nd car so relatively low mileage. Never been tracked but does get a decent drive when I do use it! Only ever put Tesco super unleaded in it as it's nearby and it goes ok for me. Am I missing something or is this a whole new debating area? The fuel going in the tankers is the same, it’s the additives that the various companies add that that varies between Shell, BP, Tesco’s etc.. Shell V power is generally believed to be the best available super unleaded. I could waffle but here it is... https://www.shell.co.uk/motorist/v-power-fuels/v-p... My 981 CS has only had Shell VP in so can’t comment re performance but... When I started using VP in my previous Audi TTS performance noticeably improved and economy was a few mpg better. The economy was neither here nor there for me, VP costs more. Personally, I’d always use it in a performance car.

Cheers, all. My only test with Super on a performance car was with my previous V8 Vantage S. I tried it with both, and it resulted in zero difference. Aston also suggest super, but when I talked to service at the dealer, they said not to bother. So long as using a lower RON rating doesn't affect some hardware, I think it's back to normal unleaded. Doubt I'll notice 0.05 seconds difference to 60

nickv8 said: Cheers, all. My only test with Super on a performance car was with my previous V8 Vantage S. I tried it with both, and it resulted in zero difference. Aston also suggest super, but when I talked to service at the dealer, they said not to bother. So long as using a lower RON rating doesn't affect some hardware, I think it's back to normal unleaded. Doubt I'll notice 0.05 seconds difference to 60 Performance aside, I'll add that on a car with a dynamic/adaptive ECU, same as yours, with RON 99 I was getting nearly 10% better mpg, at only 5% increase in cost. I use Tesco 99. No brainer.

Probably. Almost all fuel today, in ANY petrol station, comes from the nearest distribution centre (DC). So let's be clear - it's all the same base fuel. Each branded tanker arrives at the DC, fills up, and then adds it's own unique additives package. That's the only difference. Shell included. Oddly now Esso is promising E0 in their super-unleaded, but again this is geographically limited, due to what is available at the nearest DC. Greenery currently supply a large swathe of Esso branded petrol stations. Greenergy have always supplied Tesco 99. So it's all down to the tanker drivers' magic-mix. https://www.greenergy.com/greenergy-becomes-fuel-s... ETA https://www.tesco.com/help/petrol-stations/ Under UK legislation, large fuel producers have a mandatory obligation to use a certain percentage of fuel from renewable sources. The renewable fuel used in petrol is ethanol, typically produced from sugar or starch crops such as sugar cane and maize. Dependent on location and supplier, UK petrol contains between 0 and 5 percent ethanol (produced in compliance to BS EN 288:2012). Edited by Orangecurry on Monday 22 March 18:28

Orangecurry said: Performance aside, I'll add that on a car with a dynamic/adaptive ECU, same as yours, with RON 99 I was getting nearly 10% better mpg, at only 5% increase in cost. I use Tesco 99. No brainer. According to https://www.rac.co.uk/drive/advice/fuel-watch/ Super unleaded is (on average) 9% more costly than normal. But I get your point.

Currently not overly bothered although I predominantly use Shell Vmax. From September, standard unleaded is due to go E10 which I am not so happy with as Ethanol absorbs water and if you don't use the car regularly, it could separate and cause real problems.

Clever marketing (Shell)? Placebo effect? Marginal, but barely detectable, benefits in normal use? Probably all three. But, like many, it gives me a nice warm feeling when I give the cashier my credit card.

You can use 95 ron on these cars, but it will retard the timing, giving you a drop in BHP and MPG. It is a Porsche, they have been NA for years where people spend £10,000's on trying to squeeze another 10-20hp from them, and yet we have people putting in 95 ron which will loose that much from the official figures as you drive off the forecourt. Forced induction cars tend to get hit harder, but NA engines that are designed to run on 98 will lose a fair amount of HP and MPG. I rolling roaded my 335i touring a few years back as the difference between 95 and 98 was massive. It dropped 30hp on 95 ron, which was roughly 10%. The MPG went from 30-31 down to 26-27 as well, so no cost savings to be had. Tesco 99 was as good as any of the other super unleaded fuels and was often as cheap as the Shell 95. Even our E350 estate was much nicer on 98 ron. 304hp on 98 and down to 281 I think it was on 95 ron, but the MPG was the biggest change, every time I reset the OBC it would end up back at just over 30mpg using 98, where as on 95 it would end up at 26. Sainsburys fuel used to threw an EML on the Merc, and when scanned it would say the emissions post cat were too high and the suspected contaminated fuel or an unknown additive detected. The problem is it can take a couple of tanks to get it running at full steam, but even 1/4 of a tank of 95 will set it back again. Run it for a few tanks, better hp, better MPG and it burns much cleaner so far better for the car if you plan on keeping it as it gets a few years old. No brainer.

So... to confirm... diesel is an absolute no no too?

It was Tesco fuel which caused our 1yr old BMW to malfunction. Stopped using it and the issue never reoccurred.

DJMC said: It was Tesco fuel which caused our 1yr old BMW to malfunction. Stopped using it and the issue never reoccurred. What the Momentum 99 ron stuff?

Sorry, no. Diesel. The DPF became blocked. The BMW mobile technician asked "...have you been putting supermarket fuel in this?" He then explained the double refining done by Shell, Texaco, and BP only and how all the others add sulphur to their fuels to boost the octane rating. Now some "experts" here will poo poo this but he had spent 30+ years working on many different brands and just knew we were "guilty" of using supermarket fuel. Please do poo poo but also maybe add your own credentials in the motor industry allowing you to cast doubt on his assessment. So I have transferred his perfect knowledge to the world of unleaded too. Their may be no link at all, but I'm not prepared to take the risk. Prior to the BMW we had a DPF failure on an A3. Guess what fuel we used? And guess why it's cheaper?

I always add Archoil 6400D to my diesels. I replaced the gunked up manifold and EGR on my old E61 530d when I bought it with 60k on it, and when I moved it on with 118k on it I looked at the EGR and it had nothing more than a layer of dust you could wipe off with your finger. Additives make a hell of a difference, and that is what you pay for in fuel, additives. Mate of mine had no end of issues with his DPF constantly trying to regen, BMW wanted to put a new DPF in. I got him to run Archoil and it went from trying to regen every tank to every every 3rd or 4th tank.

Some supermarket fuels are brands ie Sainsburys is BP, morrisons use Shell and some Tesco have Essso

DJMC said: Sorry, no. Diesel. The DPF became blocked. The BMW mobile technician asked "...have you been putting supermarket fuel in this?" He then explained the double refining done by Shell, Texaco, and BP only and how all the others add sulphur to their fuels to boost the octane rating. Now some "experts" here will poo poo this but he had spent 30+ years working on many different brands and just knew we were "guilty" of using supermarket fuel. Please do poo poo but also maybe add your own credentials in the motor industry allowing you to cast doubt on his assessment. So I have transferred his perfect knowledge to the world of unleaded too. Their may be no link at all, but I'm not prepared to take the risk. Prior to the BMW we had a DPF failure on an A3. Guess what fuel we used? And guess why it's cheaper? I have 10 years plus working in the breakdown industry, with particular focus on manufacturer-supplied policies. Rule no.1 of delivering roadside assistance is to never, ever, criticise the brand. That includes confirming any well-known issues with a particular component (minor or major). Even for the likes of the AA or RAC, the patrols can be disciplined for concurring or implying with the owner that they've spent a lot of money on a car that is likely to break down. I know this from direct experience. So in your case, I would suggest that the BMW mechanic is playing to his employer's rulebook and blaming a third party (the fuel) rather than you the owner (for your pattern of usage) or the car (for having a component failure or not regen-ing the DPF). If you extrapolate your 100%-failure rate across two brands the wider population, then you'd be looking at the vast majority of VAG and BMW diesels experiencing a DPF-related issue. Having owned 3 x diesel BMWs (640d GC, 125d F20 and 530d F10) and a similar number of VAG diesel cars (Eos 2.0tdi, A3 2.0TDi, Ateca 1.6TDi) in the last 6 years, I can confirm absolutely zero DPF issues across approx 160k miles. All were run on supermarket fuels and used across a variety of journey types. I think, sadly, you've just been very unlucky - especially if you do regular longer journeys where the DPF has opportunity to regen.

I personally try and avoid fuels with ethanol content, so I usually stick to Esso 99/97, or if pushed go to Shell vpower. I run the lawnmower on Esso Super and it started first time last weekend, no issues with that fuel sitting over winter

Rojibo said: I personally try and avoid fuels with ethanol content, so I usually stick to Esso 99/97, or if pushed go to Shell vpower. I run the lawnmower on Esso Super and it started first time last weekend, no issues with that fuel sitting over winter I've recently switched to only putting Esso Synergy Supreme +99 in my cars due to not containing any ethanol. However based on what Orangecurry stated above Tesco's 99 is exactly the same fuel as both sourced from the same place. I'd like some clarification on this as it would save me a fair trek to my nearest Esso 99 supplier.

DJMC said: He then explained the double refining done by Shell, Texaco, and BP only and how all the others add sulphur to their fuels to boost the octane rating. Just to focus-in on this. This is factually incorrect, almost every word. He didn't 'explain' double refining, he just stated it as a fact. He's a mechanic.

Taffy66 said: I've recently switched to only putting Esso Synergy Supreme +99 in my cars due to not containing any ethanol. However based on what Orangecurry stated above Tesco's 99 is exactly the same fuel as both sourced from the same place. I'd like some clarification on this as it would save me a fair trek to my nearest Esso 99 supplier. It probably is, given how close a relationship Esso and Tesco seem to have - the Esso station close to me is actually a medium sized Tesco... Is there an easy way to check yourself perhaps, separate the ethanol from the petrol?

Taffy66 said: I've recently switched to only putting Esso Synergy Supreme +99 in my cars due to not containing any ethanol. However based on what Orangecurry stated above Tesco's 99 is exactly the same fuel as both sourced from the same place. I'd like some clarification on this as it would save me a fair trek to my nearest Esso 99 supplier. I didn't - I said that Greenergy (part owned by Tesco) have supplied Tesco Momentum 99 since it started. I said that Greenergy are supplying Esso (geographically dependent) - easy to find this on the internet. I did say that each company are unlikely to publish statements that will connect 'premium brands' with supermarket brands. I can't see how the base fuel is any different (the additives package clearly is), but that's not stating they are exactly the same. I would think, based on simple logistics, that they are. Otherwise, Greenergy have to store a E0 and an E0-E5 base fuel? I'd love to find some statements, one way or the other. Edited by Orangecurry on Tuesday 23 March 10:11

DJMC said: Sorry, no. Diesel. The DPF became blocked. The BMW mobile technician asked "...have you been putting supermarket fuel in this?" He then explained the double refining done by Shell, Texaco, and BP only and how all the others add sulphur to their fuels to boost the octane rating. Now some "experts" here will poo poo this but he had spent 30+ years working on many different brands and just knew we were "guilty" of using supermarket fuel. Please do poo poo but also maybe add your own credentials in the motor industry allowing you to cast doubt on his assessment. So I have transferred his perfect knowledge to the world of unleaded too. Their may be no link at all, but I'm not prepared to take the risk. Prior to the BMW we had a DPF failure on an A3. Guess what fuel we used? And guess why it's cheaper? Poo-pooing person here - motor industry? No. I'm an ex-geophysicist, so I know some about the fuel industry, content and supply, which is what we are talking about Where is it that you imagine Tesco add sulphur to their fuels? Behind the bread isle? It is ALL geographically dependent - Greenergy provide Tesco's fuels (unless things have changed very recently) which is why a few years ago you couldn't get 99 if you were too far away from Thurrock, which is where the 99 started to be introduced from. Greenergy have expanded ever since, and have multiple disparate distribution centres. https://www.greenergy.com/infrastructure Greenergy now supply Esso, again geographically dependent and are championing their E0 Ron 99. Tesco only claim 0-5% Ethanol, but if it is the same source still, they may change their marketing.... but remember, their target audience is shoppers who want to save the planet. Petrol to them is nearly a loss-leader, not their main business, and so can sell it cheaper. No rocket science here. Distribution. As stated, many times, there is a difference in the fuel, but it's ONLY the brand-unique package of chemicals added Bear in mind that the 'premium' brands do not want info out there that connects them to 'cheap supermarket petrol', so it's difficult to find facts on the internet. News from 2010, but it shows the interconnectivity, since when Greenergy has expanded... a lot internet said: Greenergy, which was founded as a bedroom start-up in 1992, already supplies petrol and diesel to about 20 per cent of Britain's service stations, including those of BP, Shell and Texaco. It also supplies forecourts owned by Morrisons and Asda. In 2002, Tesco bought a 25 per cent stake in the company for just £1.9 million because it wanted to be part of the move towards more sustainable fuel. At the time, Greenergy had sales of £70 million and was losing about £1 million a year. Eight years later, Tesco cemented the relationship by buying Barclays' ten per cent stake. The remaining 65 per cent of Greenergy is owned by the founders and employees. https://www.thisismoney.co.uk/money/article-1333631/Tesco-poised-dominanttakes-lead-road-fuel-supplier.html Why (and how) would Greenergy/Tesco, add sulphur to just their own fuel, which they sell to everyone else, and therefore can sell at the best price anyway? What did famously happen, in 2007, was that a batch of fuel was contaminated with silicone, at the Thurrock centre, which was at the time, as they were expanding, being used by many supermarkets, as supermarkets do not make fuel, nor do they add sulphur.. Edited by Orangecurry on Tuesday 23 March 12:36

Always use to put shells finest in my cars but since moving not any nearby but there is Tesco express with an Esso garage attached so in goes the 99 stuff does wonders in our mini f56 JCW but it seems a lot more expensive than shells finest.

On the subject of supermarket fuels in particular... Does Waitrose have better fuel than say, Lidl? Despite Lidl saying their customers can't tell the difference? And if I fill up at an Aldi, will I end up walking away with a deck chair, 4 man tent and a MIG welder from the random isle in the shop? Also who wins out of Sainsburys and Tesco?

Always use VPower/Nitro+ here ever since my E46 330Ci days as my cars have always pulled better on it - not convinced the mpg is any better unlike some who claim they almost pay for themselves. Did run my Golf R on Tesco momentum for a while though. Performance every bit as good as Shell but exhaust pipes definitely appear to blacken. It was a leased car so I wasn’t too bothered but back to Shell these days as hardly use any fuel now.

Orangecurry said: DJMC said: He then explained the double refining done by Shell, Texaco, and BP only and how all the others add sulphur to their fuels to boost the octane rating. Just to focus-in on this. This is factually incorrect, almost every word. He didn't 'explain' double refining, he just stated it as a fact. He's a mechanic. Yep, he's completely wrong, can't be a great mechanic if he doesn't understand what goes in the petrol tank!! After 30 odd years in the oil industry, mainly in crude production, I can tell you that sulphur is a nightmare for the oil and gas industry. The term sweet crude is derived from the fact that the oil has very low quantities of sulphur (usually as Hydrogen Sulphide) in it and most oil refineries now have desulphurisation plants to remove sulphur to allow them to use lower quality cheaper "sour" feedstock. Most sulphur compounds are pretty corrosive and after seeing what sulphur reducing bacteria do to mild steel at first hand, you do not want a refinery "swimming" with sulphur. By the way Sulphur doesn't boost the octane rating, just google Octane boosting chemicals and you'll find most are aromatics. Also the refining business is pretty cut throat, with pretty low returns.....no one would be doing double distillation, it would be totally pointless and a massive waste of energy for what would be a tiny (if any gain). There is the process of alkylation, where Hydrogen fluoride, is used as a catalyst, to increase the yield of petroleum grade fractions. Typically, low boiling byproducts such as propylene and butylene are reacted with isobutane to generate high-octane products.

Marvellous - so can you answer a 'current process' question for me please? Simply speaking, refineries split the crude into dozens of products, one of which is 'petrol'. This goes to distribution centres, and then into tankers (or just pipes) and then to 'petrol' stations. When in the process is the ethanol added? i.e. how can Greenergy provide their Esso+ fuel with 0% ethanol?

Holgate86 said: Orangecurry said: DJMC said: He then explained the double refining done by Shell, Texaco, and BP only and how all the others add sulphur to their fuels to boost the octane rating. Just to focus-in on this. This is factually incorrect, almost every word. He didn't 'explain' double refining, he just stated it as a fact. He's a mechanic. Yep, he's completely wrong, can't be a great mechanic if he doesn't understand what goes in the petrol tank!! After 30 odd years in the oil industry, mainly in crude production, I can tell you that sulphur is a nightmare for the oil and gas industry. The term sweet crude is derived from the fact that the oil has very low quantities of sulphur (usually as Hydrogen Sulphide) in it and most oil refineries now have desulphurisation plants to remove sulphur to allow them to use lower quality cheaper "sour" feedstock. Most sulphur compounds are pretty corrosive and after seeing what sulphur reducing bacteria do to mild steel at first hand, you do not want a refinery "swimming" with sulphur. By the way Sulphur doesn't boost the octane rating, just google Octane boosting chemicals and you'll find most are aromatics. Also the refining business is pretty cut throat, with pretty low returns.....no one would be doing double distillation, it would be totally pointless and a massive waste of energy for what would be a tiny (if any gain). There is the process of alkylation, where Hydrogen fluoride, is used as a catalyst, to increase the yield of petroleum grade fractions. Typically, low boiling byproducts such as propylene and butylene are reacted with isobutane to generate high-octane products. Very interesting. Thank you.

This is turning out to be a really interesting and informative thread, totally uncharacteristic by normal P'heads standards. On the subject of fuel i suspect i had issues with petrol in my RS last week. Its hardly been driven in the last 12 months due to our longer welsh lock downs and was SORNED. I put it back on the road a week or so ago and i had various issues with numerous warnings flashing up which i suspect was down to a battery running low due to not being used. The main issue was a warning about Reduced engine power but OK to drive. The engine had gone into limp mode and whilst operating normally at lower revs, it would not rev past 6k revs, like running into the 9k rev limiter but 3k earlier. I has Porsche assist out(AA) and he thought it was caused by the petrol had degraded in the tank due to not being driven in four months. Is this plausible or is there something else going on.? I then drove it as hard as i was able to to use up the fuel and then replenished with Esso 99. I haven't noticed the issue on the way home but i was stuck behind slower traffic so over 6k wasn't really on the cards.

Tesco’s finest for our 981 PDK usually, no problems in 18 months and 11k miles.

Taffy66 said: The main issue was a warning about Reduced engine power but OK to drive. The engine had gone into limp mode and whilst operating normally at lower revs, it would not rev past 6k revs, like running into the 9k rev limiter but 3k earlier. I has Porsche assist out(AA) and he thought it was caused by the petrol had degraded in the tank due to not being driven in four months. Is this plausible or is there something else going on.? Yes correct. The chemicals that change the RON in fuel degrade over time. I'm not sure if it can degrade below 95 - that would be down to a petroleum expert to explain.

Taffy66 said: This is turning out to be a really interesting and informative thread, totally uncharacteristic by normal P'heads standards. Totally agree. I love it when the experts pile in and squash the hearsay, internet rumours and total tosh! Shame there isn't a scientific expert on 4cyl vs 6cly exhaust notes, or manual vs pdk

Orangecurry said: Taffy66 said: The main issue was a warning about Reduced engine power but OK to drive. The engine had gone into limp mode and whilst operating normally at lower revs, it would not rev past 6k revs, like running into the 9k rev limiter but 3k earlier. I has Porsche assist out(AA) and he thought it was caused by the petrol had degraded in the tank due to not being driven in four months. Is this plausible or is there something else going on.? Yes correct. The chemicals that change the RON in fuel degrade over time. I'm not sure if it can degrade below 95 - that would be down to a petroleum expert to explain. +1 All the restoration videos and programmes I've watched change all fluids including draining the fuel tank before trying to crank the engine. The fuel degrades and also gets contaminated with condensation.

Can't believe some owners of £50k+ (when new) sports cars would even consider skimping on cheap fuel... A few years ago, 5th Gear did a (relatively) scientific test of some of the popular petrol. https://www.youtube.com/watch?v=d8L-X89duEs Spoiler alert, Tesco didn't win... I only use Shell V-Power except in an emergency (through rare bad planning) as my car was designed to run on the good stuff. Even my lowly diesel gets only Shell and has never had any fuel issues. In years previous, the odd tank of supermarket fuel has caused stuttering, hesitancy and at least 5-10% less mpg. The best fuels might not make much difference power wise, but will result in a cleaner fuel system and better burn. Happy motoring!

Jim1556 said: Can't believe some owners of £50k+ (when new) sports cars would even consider skimping on cheap fuel... A few years ago, 5th Gear did a (relatively) scientific test of some of the popular petrol. https://www.youtube.com/watch?v=d8L-X89duEs Spoiler alert, Tesco didn't win... I think you've posted on the wrong thread. Unless you've posted the wrong video? Not only was that a test of higher octane vs lower octane, it also didn't include Tesco.

Orangecurry said: I think you've posted on the wrong thread. Unless you've posted the wrong video? Not only was that a test of higher octane vs lower octane, it also didn't include Tesco. Oops, meant BP, does show a good difference between fuels though and some people are still happy to fill their Porsche with crap fuel...

Oh right you mean high RON vs lower RON? No arguments from me on that. But the fuel isn't 'crap'. It's all the same fuel.

Jim1556 said: C... the odd tank of supermarket fuel has caused stuttering, hesitancy and at least 5-10% less mpg. The best fuels might not make much difference power wise, but will result in a cleaner fuel system and better burn. I think real life experiences, like yours and mine, are more valuable than the scientific theory. Prior to my BMW DPF issue I'd followed threads like this for years (after the diesel A3 EGR valve died) and assumed all would be well with supermarket fuels as the science made sense. I could have been sceptical of the BMW technician's stance but without any clues he went straight for the cause being supermarket fuel. After moving away from Tesco we've had no DPF or EGR issues in 3 1/2 years. I use VPower in my 981, always have, so I don't know if it's better for power than ordinary fuel but my long term fuel consumption hovers around 36mpg

DJMC said: ...scientific theory . I'm out

Yes, anecdotal evidence always trumps Science.

I think the contamination episode really didn't help. As much as I've considered trying Tesco's Momentum 99 I always stick to v-power or BP.

Orangecurry said: I'm out I doubt it. Why are you reading this if you are?

Shell VPower was always supposed to have better cleaning properties (more effective cleaning agents added) than other fuels. I'm not certain if it still does but the general recommendation (among many in the GT-R community) is to fill up at least one in every four with SVP. Performance-wise, the age of the fuel can actually have a bigger effect than the brand but it's also always possible to get a "bad batch". In turbo cars (especially those with large turbos, running high boost) you are more likely to notice a difference in performance due to ambient temperature than choosing BP Super, or Tesco Momentum99, or SVP tbh. If you run with a lower octane rating and drive hard (especially with turbo cars in warmer temperatures or with high boost), it is possible that the car will experience detonation and then the ECU (on modern vehicles, anyway) will pull the timing back and you'll lose performance - in extreme cases, the car may go into "limp" mode. I fill up the Porsche the same way as the GT-R - two-or-three of every four fill-ups with SVP and the rest with a different fuel - even though it is NA and not turbocharged. I live in Switzerland now, so the reason I do not fill up every time with SVP (as I used to do with the GT-R & Evo in the UK) is because there is an ARAL 102 station up a stretch of derstricted autobahn near me and I use that to boost the average octane rating^ in the tank at any time and give the cars a proper WOT run regularly, which is also useful for high performance vehicles - if it wasn't for this, I would happily fill with SVP each time. My recommendation would always be to fill up with SVP as regularly as possible (if you can). While you are unlikely to notice any performance hike, you will benefit from the cleaning agents over the lifetime of the car ... [Caveat, if other brands are now offering as good or better cleaning with their performance fuel, that would be the best bet.] ^The GT-R has a 102 map, so gets a performance advantage from using 102 RON fuel (the timing is increased ...). However, the Porsche will not gain any performance advantage from using the 102, but keeping the average RON rating as high as possible, while maintaining the good cleaning of SVP, will protect just a little against detonation (though, to be fair, Shell VPower Racing is 100 RON here anyway).

DJMC said: Not just any Super. Shell first choice. Only BP or Texaco otherwise. Don't touch supermarket stuff. Learnt from experience they are NOT all the same. Actually I would recommend Esso Supreme 99, because, so long as you are not in Scotland, Teesside or Devon, it is ethanol free. The other good one if you happen to be in Deutschland, is Aral Ultimate 102, also ethanol free. And you WILL notice the difference with the latter. Try a quick tuning service - brim it with Aral 102 and max it on the Autobahn at 04.00 in the morning.

cardigankid said: Actually I would recommend Esso Supreme 99, because, so long as you are not in Scotland, Teesside or Devon, it is ethanol free. The other good one if you happen to be in Deutschland, is Aral Ultimate 102, also ethanol free. And you WILL notice the difference with the latter. Try a quick tuning service - brim it with Aral 102 and max it on the Autobahn at 04.00 in the morning. You'll only notice the difference with ARAL 102 if you have mapped your car for it^, as I mentioned above. It's a myth that you will notice the difference as the car will still make the same maximum horsepower unless there is an optimised map with the timing increased. If running 102 on a warm day (especially with a turbo car), you may notice the difference because the ECU will be less likely to pull timing back (the higher the RON the more resistant to detonation - timing being pulled back is often dsplayed by a flashing engine warning light when under WOT). ^My old Evo (97 & 99 maps) and the GT4 run no better with ARAL 102 than Shell VPower Racing 100. My GT-R, in the 102 map, runs better but if left in the 99 map it runs the same regardless of 102 or 100.

I swear my S sounds better with V Power!

Orangecurry said: Marvellous - so can you answer a 'current process' question for me please? Simply speaking, refineries split the crude into dozens of products, one of which is 'petrol'. This goes to distribution centres, and then into tankers (or just pipes) and then to 'petrol' stations. When in the process is the ethanol added? i.e. how can Greenergy provide their Esso+ fuel with 0% ethanol? Ethanol is added at the loading rack (imagine a massive petrol station for the tankers). It’s injected at the same time as the brand-specific additive according to a recipe. So your loaded product will be X% base product, Y% ethanol and Z% additive package. There are a handful of exceptions to this rule where the additive package will be added at the petrol station. (Also, just to correct your simplification - petrol is a blend of refined hydrocarbons. It doesn’t come straight off the process units as petrol. Rather, lots of different components are blended together) On topic - I stick Vpower in mine, but that’s only because there’s no Tesco fuel station where I live. I’d happily stick Tesco Momentum in. Edited by Jawls on Monday 29th March 17:36 Edited by Jawls on Monday 29th March 17:38 Edited by Jawls on Monday 29th March 17:39

Jawls said: Ethanol is added at the loading rack (imagine a massive petrol station for the tankers). It’s injected at the same time as the brand-specific additive according to a recipe. So your loaded product will be X% base product, Y% ethanol and Z% additive package. There are a handful of exceptions to this rule where the additive package will be added at the petrol station. Brilliant thank you. I didn't think ethanol could be added at the distribution centre because I wrongly was thinking it would have to be a very accurate %age - but of course they only have to add 'up to x%' So that's why Esso can easily provide a 0% ethanol from Greenergy.

DJMC said: Orangecurry said: I'm out I doubt it. Why are you reading this if you are? Because I've kept an eye on the thread to see if someone who actually knows about current fuel supply was going to answer my question, and then I could thank them.

Orangecurry said: Jawls said: Ethanol is added at the loading rack (imagine a massive petrol station for the tankers). It’s injected at the same time as the brand-specific additive according to a recipe. So your loaded product will be X% base product, Y% ethanol and Z% additive package. There are a handful of exceptions to this rule where the additive package will be added at the petrol station. Brilliant thank you. I didn't think ethanol could be added at the distribution centre because I wrongly was thinking it would have to be a very accurate %age - but of course they only have to add 'up to x%' So that's why Esso can easily provide a 0% ethanol from Greenergy. The measuring instrumentation on the injectors are very accurate. There will be some margin of error, but it’s tiny.

I typically use either Tesco 99 or Costco Super (97 I think) in my C63S. It does run on 95 but definitely not as smoothly, tend to only do that when in the Scottish Highlands or a Bucks to Glasgow slog (on way to Scotland) that is 100% mway idle. BP ultimate diesel also seems to make my wife'd CLA noticeably smoother too. Never seen any mpg benefit of note in either situation.

It's petrol. Put it in your car and drive your car. Leave the pub bores arguing amongst themselves as to whether they can feel 1% of performance one way or the other.

It is not 1%. Don't be silly.

Esso 99 with no ethanol is probably the best you can get now for running at full spec.

And certainly for classic cars where ethanol can damage some rubber components of the fuel system ...