Mtea

If readily available, would you fill your 981 with ethanol-free premium every time you fill up? My gut says yes for my BS. I recently found that I have 91 octane ethanol-free premium available nearby so I just filled my tank with it. I’m no expert on gasoline so current thinking from the group would be helpful.

IndigoInkTaco

I've tried it in my other vehicles. Didn't notice a single difference. If I was still running a carb'd motor, I'd use it. I've ruined so many carbs w/ that junk, it's ridiculous. Otherwise I don't see the benefit.

Noah Fect

That's what I do, but I have no idea if it's optimal for long-term engine health. The 92-octane ethanol-free gas available around here is unbranded. Maybe it has a Top Tier-grade additive package, and maybe it doesn't. All I know is, the car runs very well on it, especially in the 2000-3000 RPM region where acceleration doesn't seem as smooth on name-brand gas.

Part of the dilemma is that I don't understand what the additive packages do in a DFI engine, where the valve mating surfaces never see any fuel exposure.

Mtea

Noah, that’s pretty much my thinking. The station here notes on the pump that the E-free premium is not a Chevron product. Perhaps there is a fuel treatment or injector cleaning treatment that I could add from time to time in case the non-branded product doesn’t have that. Another factor for me is that if I leave the car sitting for a month I am less concerned about the gas going bad.

Noah Fect

Agreed, it seems like you'd be safe by going with the ethanol-free fuel and adding some Techron every so often, just for the injectors' sake.

I have repeatedly asked some of the well-respected tech gurus on the forum how to resolve the conflicting advice between "Use ethanol-free gas when possible" and "Always use Top Tier fuels," but have never managed to pin any of them down on it. Usually that means nobody has actual data.

ztnedman1

Ethanol has an octane of 105.

Ethanol is oxygenated, so adds O2 to the combustion process.

Ethanol runs cooler than gasoline, preventing detonation.

In DI injection the cooling effect from ethanol is optimized creating additional gains.

The extra fuel added also helps cooling and technically increases compression due to more fuel in the camber(negligible).

The 10% E is boosting lesser gas(to make 93...or 91 puke), but it is so far and above better it makes a better product. Especially in DI engines.

In WW2 the collective "we" knew straight gasoline was insufficient in performance and started adding lead to avoid detonation and performance loss.

Ethanol can capture water into fuel. A little water is just fine. A lot of water is not...do not use in marine applications.

Ethanol has terrible lubricating properties. It also ruins the lubricantion properties of gas and oil. Do not use in 2 strokes.

Ethanol will clean gasoline gum deposits. Gas will clean ethanol gum deposits. If this happens post filter you will get blockages. Keep in mind for use with carburetors, especially those that sit frequently.

Ethanol is a political land mine. Made with subsidies using a critical food crop in NA...not a great use case.

If your car is fuel injected, forced induction, direct Injection, or a combination then ethanol is a +++. You want it, there are no negatives in a modern car.

Mtea

Ztnedman1 thanks for the detailed info on ethanol gas. With your info I will use the ethanol gas without worrying. If one cleans the other would it make sense to run a tank of ethanol-free once in awhile? Maybe a gas treatment occasionally? Or does name brand gas have enough additives to keep the injectors, etc. clean.

Agree on the political bit. My wife was in the food industry and saw the price of corn shoot up when government got behind ethanol gas. Alternatively, ethanol can be made from natural gas. We have a lot of it, nobody eats it, and some say it’s cheaper to make than corn ethanol. Further, natural gas is often used to heat the corn biomass to create the ethanol. Similar to electric cars being green if you only look at the driving down the road part. Don’t look behind the curtain to see where the batteries and electricity come from.

rockhouse66

If you really want the whole scoop, watch this;

https://www.pca.org/news/what-you-ne...h-tactics-live

TEF

Where I live ethanol-free gas is plentiful because it's commonly used in pleasure boats, but it is only 91 octane. However, I use it for small engines (mower, snow blower and chainsaw) and fill my 981 BS each fall before putting car into storage. Frankly, it seems to perform in the Porsche about the same as Shell premium, but costs more since one is buying more petroleum per gallon vice gas and ethanol. In my opinion it's great for small carb'd engines and outboard boat motors.

rdboxster

I use non-oxy (ethanol free) gas when I store the BGTS for the winter. It has a longer shelf life but I still add a stabilizer. If you have low usage with ethanol gas it’s important to add a stabilizer. Also ethanol fuel is good to use in the winter especially if you park in a warm garage and drive in cold weather. I know of cases where there was fuel line freeze ups. Ethanol helps prevent by removing the moisture. The original intent of ethanol in fuel was to help reduce pollution during cold start ups especially in the northern climates. Wasn’t supposed to be used in summer months but that’s all changed. Vehicles today are designed for it so not a problem.

tomekz

I know this isn't some multi billion company doing the testing on the fuel stabilizers, but his tests do not show any positive advantage off using fuel stabilizers especially to help remove or reduce water in the fuel and/or prevent ethanol damage. And yes, ethanol is not really good for our engines.

Look up 'ProjectFarm' youtube channel and search for "Does Fuel Stabilizer Prevent Ethanol Damage? Let's find out!" video

Last_935

I try to run ethanol free gas in my vintage cars whose fuel systems were designed before ethanol fuel was the norm. I prefer Top Tier, high octane fuel over lower octane ethanol free gas in my cars that were built to run on fuel with ethanol.

thecajunboy

Interesting comment. Ethanol free in my area is only available at 91 octane. The comparison you mentioned to name-brand gas, what was the octane rating on those? I've always used Top Tier 93. Can't say that I've experienced a lack of smoothness in that range, but I may have to run the tank down low and give this a try.

Also I'm in a 2.7 base. Not sure what engine you're running.

Noah Fect

3.4L in my case. Nobody seems to sell 93 in this part of the country, for whatever reason, even though it's factory-specified for my 3.0L Macan S. So I can get unbranded 92 sans ethanol at the local farm co-op, or name-brand 92 at the usual stations.

The ethanol-free place is a dozen or so miles away, so I don't generally bother putting it in the Macan, just the 981.

R-GT3

Love the attention to detail on your wiring of the Bosch extender connectors. I'm having trouble locating an affordable crimping tool for my wiring project, do you recall where you purchased yours?

Thanks...