The Stovebolt Site Forums The Shop Area General Truck Talk "Gasahol"- 10% Ethanol Gasoline

Hi Guys,

A friend mentioned that gasoline mixed with ethanol will dissolve diaphragms, o- rings, and rubber gas lines found in old vehicles. That means fuel pumps, carburetors, etc. will eventually fail. Is he correct about this?

I am sure you guys have discussed this before. If so, please guide me to the proper link.

Thanks,

Jon

Yes, it is true. Older rubber componets do not hold up well to exposure to alcohol, be it ehtanol or methanol. MTBE is also very bad for rubber (not used anymore). Newer rubber materials are resistamt to it, but not all carbs/feul pumps are being made/have rebuild parts that atre made with the new style rubber. Ethanol and methanol is also corrosive to metal components, especialy aluminum, though I have been told that it's only a real issue if a vehicle sites for an extended period of time with out use. Rod and Custom recently did an article about this subject, with listings of what popular vintage carbs have ethanol compatible parts available.
Others will probably chime in on this.
BTW, we run 10% ethanol here, so far, I have not had any adverse problems with my feul pump of re-built Holley carbs.

If you're not in a state where corn is a big industry, there are probably no tax breaks for ethanol and it probably isn't used. Here in Texas it is used in the Houston area to meet emissions. I am a gasoline distributer about 60 miles north of San Antonio and none of the terminals I pull out of have ethanol. It was tried here in the 80's to please the tree huggers, but it was a real disaster. Diamond Shamrock, which is now Valero tried the ethanol and called it "white lightning" They lost a lot of customers and lost a lot of money on the deal. All of the old storage tanks still had lead residue from the old leaded gas and the ethanol dissolved it. There were lots of 50's and 60's vehicles in daily service around here then and it really played havoc with fuel pumps. In the late 80's and early 90's it got to where we couldn't get liability insurance on the older tanks and almost all of the storage tanks in service now have never had leaded gas in them. I am not going to market ethanol unless I am forced to.

Thanks for the feedback. I will try to get rebuild kits that are compatible with ethanol.

I just had to order a replacement hose that connects the gas tank to the filler neck, the old one (0nly 2 years old!) had dried and cracked on the inside. I thought the old one was just junk, maybe it was the new gas.

I've read that 10% ethanol won't hurt. Take that with a grain of salt because I'm not an expert but I use it on occasion in my 38 & have had no issues because of it.

Don't mix ethanol with salt

i supposed that is why my new (4years old) fuel pump failed after sitting during the rebuild. ron

It sounds funny but my oldest daughter lives SE of Houston and I went for a visit. Before I came back I filled up at a Shell station and it had a sticker on the pump saying this fuel "may" contain up to 10% ethanol. OK no problem '05 Chevy 2500HD w/6.0L normally lousy mileage, 14 mpg on the way down but 16 mpg on the way back. Is this a bad thing???

Ya must have had a tail wind blue.
Denny G

Let's keep it related to use in our old trucks, please.

I'd guess he was towing an old stovebolt when he got the 16mpg... :-)

I run 10% as it is all that's available here due to state requirements. The truck runs fine on it. I get around 14, give or take.

I use the 10% ethanol stuff in everything I own with exception of two cycle engines. I have had no problems with it. In fact, if I use straight gasoline in my 261 it will ping unless I back the timing off or take it easy. I get 20 mpg on the highway so I am satisfied.