Reg vs Prem

[GH85Carrera]

Originally Posted by speeder

Every single gasoline vehicle in CA. runs on 10% ethanol full time. That's every single police car and taxi that runs around the clock 24/7, Every Charger Hellcat and McLaren or Ferrari, every Porsche including modified air-cooled, etc. And every motorcycle. I don't like that ethanol is required in our fuel, (reduces energy concentration slightly), but to fear running it is an old wives tale of the gear head set. It makes zero difference and actually is the easiest way on earth for refineries to add octane to gasoline. E85 would be an example of this.

We drive a hell of a lot more miles than people in the state of Oklahoma or just about anywhere else in the USA. That said, I'd love to be able to buy pure gasoline, (especially for fly-over prices), and grab it anytime I'm out on the road burning gasoline. That is rare, though, almost everything I own burns diesel.

Old cars biggest vulnerability was the old rubber hoses that ethanol ate up. Once updated to new alcohol resistant hoses, no big deal if the car is driven regularly. It is a big deal if it sits over the winter and water condensation is high. Ethanol is corrosive, and can damage fuel system parts.

Talk to any small engine (lawn equipment) engine repair. They will have lots of horror stories of Mr. average homeowner that lets gasohol sit in the equipment over the winter. Especially in older lawn equipment. I have a 3.5 HP edger I use on the 1/4 mile of edging at my house. It was bought new in 1988. Starts on the first pull. It has never seen gasohol.

So yea, all modern cars, no problem at all with E10. Even my 85 911, no problem but the rubber hoses are all replaced.

[masraum]

Originally Posted by David Inc.

For modern cars, yes. They can watch for knock and pull ignition advance when they see it. It means less power and efficiency, though, and isn't good for the engine itself. I think mine says it can run on regular in a pinch but it's advised to refill with premium ASAP, '17 Alfa Romeo Giulia.

I think Otter was talking about "premium fuel recommended" vs "premium fuel required." Yes, a lot/most modern cars can adjust for the difference.

[speeder]

Originally Posted by masraum

Isn't ethanol less energetic, and has the effect of raising octane which reduces likelihood of knock. If you're going to have knock with 87octane 10%ethanol, you're going to have knock with 87octane 0% ethanol, right. So ethanol vs none doesn't really change knock characteristics for a given octane rating.

So whether running 87 or premium (91, 92, 93) it makes no difference if it's got ethanol or not (from a knock point of view).

This is correct. No difference.

Originally Posted by GH85Carrera

Old cars biggest vulnerability was the old rubber hoses that ethanol ate up. Once updated to new alcohol resistant hoses, no big deal if the car is driven regularly. It is a big deal if it sits over the winter and water condensation is high. Ethanol is corrosive, and can damage fuel system parts.

Talk to any small engine (lawn equipment) engine repair. They will have lots of horror stories of Mr. average homeowner that lets gasohol sit in the equipment over the winter. Especially in older lawn equipment. I have a 3.5 HP edger I use on the 1/4 mile of edging at my house. It was bought new in 1988. Starts on the first pull. It has never seen gasohol.

So yea, all modern cars, no problem at all with E10. Even my 85 911, no problem but the rubber hoses are all replaced.

I've been hearing this forever and it's BS in my vast experience. I've owned or worked on over 100 cars since the advent of ethanol fuel and the truth is that old fuel lines dry out and leak while newer ones do not...regardless of ethanol in fuel. I just put an MG back in service last month that had been sitting for over 30 years, in Minnesota. Minnesota still has non-ethanol fuel available in 2022 and the 1975 MGB owners manual specifies no unleaded fuel, much less ethanol. Obviously, this requirement became impossible at the pumps shortly after the car was built.

Anyhow, all of the fuel lines were old and needed to be replaced. It was obvious that they were dangerous and would have leaked, because they were old. I've never seen fuel lines that were not old leak on any vehicle, with very rare exceptions that had nothing to do with ethanol. Old rubber fuel hoses dry out and leak, period. Including on diesel vehicles, all the time, which do not have ethanol in their fuel. Small amounts, (10%), ethanol in fuel will never make good fuel hoses leak. Every gasoline vehicle on the road in CA would be leaking fuel. It's an old wives tale with zero validity.

I hate that we are forced to buy ethanol fuel because it's inferior from a mpg standpoint and I think that the whole ethanol subsidy program to corn farmers is massive govt. corporate welfare but the leaking fuel line argument is BS.

[stevej37]

90 cent difference between reg and prem here today.

If gas goes much higher....the diff will be $1.00

[flipper35]

Here in the midwest you do have an issue with water and alcohol settling out together and freezing. You also have a gel that can form which will cause all kinds of havoc with the fuel pump screen. I know as I have experienced both issues here.

E10 can be hard on carb parts as well. Newer coatings not so much, but you do have to be careful.