E15 Gas This Summer

Biden just announced he's upping the Ethanol content from E10 to E15. Concerned it might do damage to our P-cars. How do you feel about it?

No, they're changing the rules to allow 15% ethanol during the summer. Previously it was only allowed in the winter. It's not a requirement either way, and E15 is pretty rare. Personally I've never seen anyplace selling E15 in California.

This is a great question. And this isn't just limited to us, it's very far reaching Most fuel lines, as far as I know, aren't designed for anything over 10% ethanol. Following.

Seems like lots of things would need addressed. Signage on pumps. Do storage tanks have to empty and then refill? Especially if you don’t want to use ethanol? If damage occurs. Who is responsible if it’s just “put” into the tanks at Filling stations. Motor boats especially do not need ethanol.

I know, the EPA said "most cars" after 2001 are compliant, but that's not true. Certainly, my 987.2 is not (according to the manual)... but neither is my wife's Jetta SE 2.5. That's not even a high performance vehicle or anything, which makes me wonder whether this statement is even true. In any case, it seems that E15 will only be offered where it was previously... and it's an extra option, not the "standard" offering (ie, E10 shouldn't be going away). But it is concerning for sure. In my area (CT) we don't normally see E15 ever, but I will have to keep an eye out. This reminds me of the old 85-octane I had seen back in the day in NY. I didn't know who would use that, but I certainly avoided it as I didn't know of any car that supported that officially, but hey, whatever. As long as the existing standard doesn't go away, they can do what they want...

I think all that may be happening here is temporarily E10 year round. Not E15.

E15 is a specific fuel, like E85, and it's only 88 octane, so you shouldn't be using it anyway. Normal premium fuel will still be max 10% ethanol.

Ethanol-free gas stations in the U.S. and Canada

I wonder what Porsche says about using E15? Does E15 affect direct injection motors more that port injected ones?

I've been using 90 octane Ethanol-free gas for a few tanks now as my grocery store changed their pumps to add it and I get the reward points . Saved 60cents a gallon the other day. I have not noticed any perceptible difference from the normal 93 octane 10% ethanol premium I used to use.

Good info. I'd expect the 90-octane may be forcing the engine to detune for knock.. which would cost some performance. Given that, the only difference I'd expect you to see is an improvement in mpg. I would be interested to hear if that is affected.

I believe that 2019 and newer Porsches are designed to accept E15. It shows up here in the midwest regularly as a "mid-grade". The pumps are always clearly labelled so that it's easy to avoid.

From LN Engineering : " Porsche only approves the use of E10 for watercooled engines starting with the Boxster in 1997 and the 911 (996) in 1999 and all subsequent models. Older Porsche models are approved to use only up to 5% ethanol. Under no circumstances should you ever use E15 fuel in any of your Porsche vehicles (or any car not designed to run E15), otherwise you may damage fuel system components or cause engine damage." FWIW I'm in Memphis and have never seen E15.

That is why we are discussing the possibility of the gov changing the rule about E10 to E15 starting in the summer. Maybe my distributors locally will have a E-15 92 octane available. My engine then can add spark advance as the ethanol runs cooler and has less spark detonation issues from my research. The downside is water retention in ethanol.

Thanks for that info, Bill. That was my assumption so I'll be using non-ethanol gasoline this summer!

Ethanol itself is a joke —an answer to a question no one asked. It takes more energy to produce than it returns as a fuel. I tolerate E10 because our cars were engineered to tolerate it. If they roll out E15 in my area I’ll be looking for the highest octane PureGas offered in my area.

About 1.2 gal of E85 to 1 gal of Petrol....

Scott, I have your race kit on my M97 engine and an updated Softronic Flash. Now, could you supply us with new fuel maps that take advantage of E-15 Ethanol properties. Give us some ideas on what the benefits of your new flash would do.

Just more political pandering.

Until you see the E-15 EPA sticker on the gas pump in a few months. News letter from LN Engineering . Only picture copied. You can go on their web site and read the Tuesday news letter yourself. Charles states the EPA has the authority from an emergency waiver on April 12, 2022. So call it however you want until you see the EPA E-15 sticker on your local pump. Of pressing concern to all owners of classic cars is the latest emergency waiver allowing for year round sales of E15 fuels that went into effect on April 12, 2022. For those who do now know, E15 was approved for use in 2001 and later vehicles by the EPA in June 2011 , however Porsche only approves the use of E10 for watercooled engines starting with the Boxster in 1997 and the 911 (996) in 1999 and all subsequent models. Older Porsche models are approved to use only up to 5% ethanol. Under no circumstances should you ever use E15 fuel in any of your Porsche vehicles (or any car not designed to run E15), otherwise you may damage fuel system components or cause engine damage. Don’t believe us, check out the After Sales document below or Porsche’s press release on the Compatibility of E10 fuel with Porsche vintage cars and recent classics .​ ​

I'm surprised that the most recent Turbocharged Porsches would have a problem with E10 or E15. As valid as most objections are to ethanol in gasoline, the turbocharged engine can leverage the advantages of ethanol with increased boost and/or timing. The zealots will even upgrade their fuel delivery components in order to run E50 or more. I would have assumed most current model cars/trucks could handle E15 without damage.

Ethanol is a joke like others have written. Additionally, you get less on gas mileage when you use it so it actually costs more to use than the small per gallon savings at the pump per gallon. I would never put this in a Pcar unless there was no other option.

I am fortunate where I live as there is a a local refinery that produces ethanol-free gas (mostly for the large number of boaters in the area) and it's available at most local stations. It actually costs more than premium, but I suspect that's because one is buying more gas and less ethanol per gallon. In the summer, I try to buy Shell premium, but store my car each winter with a full tank of ethanol free fuel. It's also preferred by contractors using chain saws and mowers as it does less damage to rubber parts in small engines. While it is only about 91 octane, it behaves like Shell premium when driving my BS. I am told that some dealers (not around here) offer ethanol-free aviation fuel at a much higher octane, but it sells for $8 to $10 per gallon.

Sure, we have a corn shortage brewing so lets up the ethanol content in gas. Who cares what it does to their fuel system in their cars. Get over to plug in faster. Keep it quiet.....the plebes won't notice a thing.....

Currently, the vast majority of aviation gas is leaded, so don't try putting that in your car. A handful of places sell 94 octane unleaded, but they're few and far between. 100 octane unleaded is going to become much more common in the next few years, as it is supposed to be the replacement for the current 100 octane leaded fuel, but it's brand new so it'll be a bit still. Pretty soon though, every small local airport in the country will have a tank of unleaded 100 octane gas on premises. All you'll need is a credit card, a gas tank, and a confident look on your face.

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LN Engineering recommends using additive for your older Porsches, Carb Defender or Injector defender if you have to use the higher E fuels.

From previous research I had done I thought E10 or E15 was not designated in premium fuel - has this changed?

Unless you run a turbo, avoid E10 or E15 if you can. Your naturally aspirated engine will thank you. You get more bang for the buck and your spark will not be retarded as much.

The only non ethanol gas around me is 90 octane but not Top Tier. I suppose I could add an octane booster and PEA additive instead of using Top Tier with ethanol (which is a lower RBOB) but is quite a hassle. Lake Speed Jr. shares his thoughts here. (Spoiler—he likes Shell V-power 93 but will use any TT fuel). Shawn in VA (USA)

Unfortunately not the case. There is no ethanol-free fuel to be found in many northeastern states (like NJ) except at airports, but that usually has lead which will poison your catalytic converters.

This video is great. Explains the ethanol issues well. He did not explain the difference in injectors between direct injection and port injection and carbon build up on the intake valve when talking about gas additives (poly ether amine). They will not prevent the carbon build up on intake valve stems on direct injection motors. That another topic related to engine oil not gas or gas additives. Also, Lake's explanation of start up on cold days, the M97 engine should be driven slowly away as soon as the RPM lowers for the catalytic converters to ignite (about 20 seconds) to lower the bore scoring potential. Most important is not to use much throttle until the oil is warm. We want to protect the plastic matrix piston skirt coating as much as possible with warm oil, not fuel from ring leakage. My question is how can we find the ingredients of the mixer distribution facility. I have two top brands, Mobil and Chevron . They most likely use the same gas stock to mix as Lake mentioned 2700 gal of gas stock, 300 gal of of Ethanol and some other additives to help, maybe Poly Ether Amine as a cleaner. Both pumps say 92 Octane and I'm at sea level. I have a 2007 987.1 S Cayman getting 21 mpg average. I know of 1 station that sells no ethanol gas but only 87 octane. I do use liqui Moly 2007 Jectron additive every 3rd tank of gas to keep my injectors clean. I'm using the Softronic Race package of a 78 mm GT3 throttle body and customized fuel delivery maps, ignition timing advance, vario cam plus starting at 3500 and retuning the intake resonance valve wave to match the Soul long tube headers .