Vintage Mustang Forums banner

type of gas for a restored 66

3K views 23 replies 14 participants last post by  myfirstcar66 
#1 · (Edited)
While picking up my newly acquired 66 (a T refitted w a 289 4 barrel), I happened to look at the fuel gauge and realized that I hadn't confirmed the type of gas to use. I had inquired about any resto documentation while inspecting previous to buying the car months ago, and the broker stated very little other than some maintenance records/receipts. He told me it was owned by a elderly gentleman who had recently passed and I got the impression he was selling it on behalf of the family. And here's where the assumption adage rears its head, I assumed that I would be using Hi-octane leaded gas. My concerns, which is present due to my inexperience in vintage car ownership, is in using un-compatible gas (leaded vs unleaded ethanol) and the damage that may occur. Thru the few maintenance records that I have, I've narrowed the restoration date between 2006-2008, with the mileage @ 7900. And I guess that I'm reasoning that the person(s) who did the restoration (and in my eyes a very complete and clean result) would not fit a used engine vs a rebuilt (there goes another assumption). I understand that during rebuilding of engines and carbs that there are steps to fit for the use of ethanol gas (seals?/hoses?/????). I'm returning to the broker tomorrow to see if he has any knowledge of the type of gas to be used, perhaps a family member informed him of the type and/or if he had gassed the car up while he had possession (altho that doesn't qualm my fears if he wasn't sure and he suffered from the assumption trap. So I'm left with asking what damage may occur or has occurred and are there any ways thru inspection to find out what gas needs to be used. You guys set the bar pretty high on my last post (ref: subframe connectors) with your wealth of knowledge and lord knows I need it again. Thanx in advance.
 
See less See more
#2 ·
Don't know where you are living and driving, but as far as I know there is no leaded gas available in the U. S. ... tetraethyl lead, or "lead" in gasoline was an upper cylinder lubricant that basically acted as a cushion for the valve against the valve seat and for the valve within the valve guide. Problem was the stuff is bad for the air we breathe. The addition of hardened valve seats and bronze valve guides negated the need for this and are a part of new cars any good engine rebuild in my experience (even though it has been a while). There are plenty of additives for fuel to replace this if those changes were not incorporated in your engine build. However, my only recommendation is using non-ethanol gasoline if available. Even in 87 or 89 octane trim it will still keep stock to mild engines happy with compression ratios under about 10:1. The 289 was originally rated at 9.3:1 I believe. The non-ethanol gas costs a little more but doesn't bond with atmospheric moisture, evaporate from fuel bowls etc so quickly or dry hoses and seals so fast when sitting in storage, as our beloved old cars sometimes do. There are fuel additives for storage also, but you'll have mixed reviews on those. For short storage, keep the tank slam full of non-ethanol. For long term, maybe empty everything and seal it good. Oooorrrrrrrr...just drive it and enjoy it year-round like I do !!
 
#3 ·
I agree with using ethanol free gas. Yes, a little pricier but given I don't drive my classics that many miles compared to my daily driver, it is easily justified. I also use ethanol free in my lawnmower too --- lol. Dean
 
#5 ·
Reading the above suggestions, I feel less concerned about my situation. I'm near Cleveland, Ohio (so year round is out, unfortunately). I've found real or pure gas, 90 Octane (ethanol free) w/i a 10 mile hop from my place. Why I associated that w "leaded" is beyond me. Perhaps its due to having asked and read about Octane boosters w some "not street legal" brands that contain lead additives. I intended to use the "milder" of the brands that claim to boost the Octane a point or so, and as 66sprint200 mentioned, the cost is minimal due to only expecting to fill the tank 3-4 x's a season. Thank you sirs, for taking the time to respond. And with the way I've started out, I expect you'll see more posts from myself in the future! HaHa. Take the odds. Again thanx.
 
#6 ·
Reading the above suggestions, I feel less concerned about my situation. I'm near Cleveland, Ohio (so year round is out, unfortunately). I've found real or pure gas, 90 Octane (ethanol free) w/i a 10 mile hop from my place. Why I associated that w "leaded" is beyond me. Perhaps its due to having asked and read about Octane boosters w some "not street legal" brands that contain lead additives. I intended to use the "milder" of the brands that claim to boost the Octane a point or so, and as 66sprint200 mentioned, the cost is minimal due to only expecting to fill the tank 3-4 x's a season. Thank you sirs, for taking the time to respond. And with the way I've started out, I expect you'll see more posts from myself in the future! HaHa. Take the odds. Again thanx.
you may want to consider adding your location to your screen name info
 
#8 ·
I am also outside of Cleveland... where is the ethanol free gasoline? The only one I know of is Cuyahoga Landmark in Strongsville, they sell 89 Octane Marathon gas without ethanol... it is a 10+ mile drive for me, I go there to get the ethanol free gas for my lawn mower and trimmer.. 10 gallons lasts me a year
 
#9 ·
The most commonly available leaded fuel is 100LL(Low Lead).
It will have a light blue color to it, but that's just to differentiate it from the other,lower octane, aircraft fuel.

Don't have a stroke when you see it going for somewhere around $5, although it varies widely with each airport.
 
#10 ·
100LL has WAY WAY more lead than automotive gas ever did, by the way. And in most states it's probably illegal to use in road vehicles, since the highway gas tax hasn't been paid on it. Personally, I wouldn't bother. We've been living without leaded gasoline in cars for decades now. If you can get it, I'd run non-ethanol unleaded premium, 91 or better octane. Should be fine.
 
#13 ·
The one and only reason tetraethyl lead was added to gasoline in the late 1920’s was simply to make cheap higher octane gasoline and nothing else. The problem the auto industry faced was the low octane unleaded gas would only support about 5.5:1 compression without the engine detonating. Ethanol was being considered being added to boost octane. But Thomas Midgley who worked as a chemist for GM pushed for lead ignoring the heath risks. Several people working on the project died and Midgley had lead poisoning.

The automotive engineers were very well aware of exhaust valve and seat erosion with unleaded gas. However the lack of lead they discovered was not the cause of the erosion. They discovered the cause was detonation. It would cause micro welding between the valve and seat was the cause of erosion. If the engine did not detonate even with unleaded gas, there was no micro welding or valve erosion. So if you don’t detonate, no problem with unleaded gas.

I never ever worried about unleaded gas. The big problem when unleaded gas came out in the late summer of 1974 for the 1975 new cars running on unleaded was the low octane. Almost all was 87 and for a lot of high compression engines from the 60’s not enough octane. Plus it cost more. By the late 70’s and early 80’s lead was being phased out from all gas and octane was dropping. We use to play the game of mixing unleaded with leaded gas as the unleaded was very receptive to lead and the net result was a higher octane over all and higher then the leaded gas’s octane too.

Burnt exhaust valves and seats were still common issues even with lead. Valve jobs were common on older motors.

https://en.m.wikipedia.org/wiki/Thomas_Midgley_Jr.
 
#15 · (Edited)
The two posts that precede mine (Huskinhano and Woodchuck) are pretty much all you need to know...

Don't worry about lead.

Ethanol is indeed a concern, but mostly if the car is not driven frequently, and the gas therefore cycled frequently.

Your best bet is a tank-full of non-ethanol 90-octane. And if the car runs right (i.e. no detonation/pinging), then you don't need to add any additives whatsoever. Save your money.
 
#21 ·
Thanx for the advice, took it this afternoon, filled up w 90. I had a little less of a 1/4 of a tank of what I know was a minimum of 7-8 month gas so I threw in a bottle of a mild Octane booster to maybe compensate. Wont use the booster the next tank so I can monitor the performance of 90 only. Thanx again. All of the advice has been reassuring to this novice.
 
#24 ·
There is a website, I think pure gas dot com, that allows you to find no-E stuff nationwide. A sure bet is someplace near water so people can get it for their boats and personal water craft.
 
  • Like
Reactions: allsixofus
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top