What Gas will be good to use for a 1970 Oldsmobile Rallye 350?
In today’s gas stations? Nov, 25th 2019.
Thank you

 

I would use 92/93 octane Non ethanol. Cars from 1970 and back were not set up to run ethanol based fuels.

 

In many places that is a lot easier said than done. If you can get it then that is what I would run. When you say 1970 and back I think you are thinking of unleaded fuel. Different thing than ethanol.

 

Totally confused, do I try to get gas without ethanol?

 

Sorry to confuse you. If you can get gas without ethanol that is the best thing to run in your car.

 

Buy "Top Tier" fuel, as it has more detergent for a cleaner engine. EPA sets a minimum detergent level, and Top Tier fuel has more than the EPA Minimum. Buy the minimum octane you can get by without detonation (pinging). If possible, "Top Tier Regular" would be a good choice. If you get ping, "Top Tier Midgrade" or "Top Tier Premium" will be needed.

https://www.toptiergas.com/licensed-brands/

Some gas stations advertise "Top Tier Plus", which has more detergent than the Top Tier standard.

I have run E-10 as my fuel of choice for almost forty years. There's a lot of crying and whining about Ethanol in gasoline, and most of what you hear is a distortion of the truth.

The first few months of "gasohol" that I bought in '79--'80--'81 was with 5% Methanol. Never had a problem, but 10% Ethanol replaced 5% Methanol fairly quickly. In the early years, SOME folks had problems when the Ethanol content of the gasoline "cleaned-out' the gas station's leaky, sub-standard underground tanks. The most recent event like that that I know of happened to my Uncle, about ten or fifteen years ago, in/near Denver CO. The EPA has forced gas stations to install better tanks with moisture sensors, so this sort of thing is rare today--and it was rare twenty years ago. But I heard a lot of complaints in the mid-'80s.

I've run E-10 in Rochester, Holley, Keihin, and Mikuni carburetors; 1, 2, 3, and 4-barrel, and a Tri-Power system. I've used it in TBI, batch-fire, and sequential fuel injection. I've used it after it's been in my plastic "lawn-mower" jugs for months. I try to not let it get older than a year before dumping it into my TBI pickup. (I store about 30 gallons of gasoline in 1, 2, 5, and 7-gallon plastic jugs for use in lawn equipment and a portable generator.)

SUSPICION without proof: I think some areas of the country are getting E-10 with some kind of industrial waste/toxic sludge. The "mystery ingredient" is causing problems, and the Ethanol is getting blamed for it.

Ethanol in gasoline is horrible farm, fuel, food, economic, and environmental POLICY. The government should not mandate blending "oxygenates" into motor vehicle fuel for multiple reasons. HOWEVER, E-10 is a fine fuel that causes non-feedback engines to run a touch lean--2 or 3 percent lean. It has less heat value than "pure" gasoline, so fuel economy also goes down a little.

Some folks act like E-10 is like filling your tank with battery acid. Forty years, multiple vehicles including small engines, and I've never had a fuel system problem I could blame on the alcohol.

I had a bad batch of gasoline in my boat. Full of water, engine stalled. That was the one and only gasoline fill I ever did at that marina, and the problem was their underground tanks, not the alcohol content per se.

I had a weed-wacker that developed hard, split fuel hoses. ******' cheap-junk Communist Chinese fuel hose. Replaced it with different Communist Chinese fuel hose, (because there's no such thing as quality fuel hose available in that tiny size) and "so far...so good" on essentially the same fuel.

My portable generator plugged the carb. Turns out, the foam the manufacturer installed in the fuel tank disintegrated after a dozen+ years, and the mush moved down-stream to the carb. Far as I know, fuel tank foam isn't intended to last for a decade. They should never have installed it in that gas tank.

The only reasons to avoid E-10 are political and environmental. Unless the fuel in your area has the "suspected mystery chemical" added to it. Around here, E-10 works just fine.

 

X2, however I've only used it for the last 15 years when regular unleaded was no longer available in Mayberry, . Here in Oklahoma non ethanol is available but they have no 93 octane, so I had to detune my engine a little.

 

I don't run the E10 in my 71 but I run the E10 in my 96.

 

Best I can find around here is 89 non-ethanol, so I'm stuck with that.

 

The liquid kind. The kind that comes out of the pump.

I've been putting whatever is available at the local gas station, regular grade or premium grade if the latter is called for, in all of my cars, new and old, since forever, and I've never had a problem. In my opinion, people stress way too much over this issue. Our cars are hardier than we give them credit for. Put gas in it, drive it, and don't worry about it.

 

Hi,

I run 91-94 unleaded for normal driving, 89 non-ethanal is the only non-ethanal available in my area
I drive my cars 5-10 thousand.miles a year and haven't had a fuel system issue.

I usually use sta-bil with premium unleaded to store my old cars in the winter. And start each once a month.

Issues with ethanol is it eats seals and rubber products, use fuel injected rated rubber lines in place of normal rubber lines and the highest octane you can get, just be sure to drive the car if it's a trailer mostly add something to like sta-bil each time or 89 non-ethonal along with octane boost additive.

Regards,

 

92 or 93 Ethanol-free is all I will run in anything not rated for it to include yard/garden equipment.
The Olds gets nothing but ethanol-free with Octane boost or the occasional sip of Sunoco 260 as I have very high compression.

 

I run 89 E10 punp gas for years. No issues! I also been adding some ethanol treatment to each fill up in the proper ratio.

Pat

 

I run 93 Octane on mostly E-10 availability, on all of the classics I have owned. No issues.

 

Just here to say the e blend fuels are only an issue if car sits longer than 3 months. Solution is to drive it more lol. I run 93 e blend on my 10.25 to 1 compression 350 olds powered drag car. I take it for a drive a few times each month even in the winter if its above 20 degrees. The whole e blend fuel debate is kind of squashed because all the info is out there. Just fwiw.

 

It may also depend upon the climate. These days my car sits in the garage through the brutal summer, which is usually 5 months long, and I have never experienced any issues with the E-10 gasoline we have here in Phoenix.

 

I wish I could pump coal into my tank.

 

I use regular gas, 87 octane, on my stock 350 and 468. They both have low compression and it doesn't ping.

 

Hondo our cars need high octane gas period. We have no option but premium, hi test, super, whatever they call it. Even then we can still have issues... Once filled up with premium in New Jersey without verifying the octane. My car did not like it, pinging, run on, dieseling you name it. Turned out it was 92 octane.

If your car is factory set like mine, stock timing, points, etc. 93 octane is a must, or as close as possible + a booster. 93 is readily available by me but the car still runs smoother with an octane booster on every fill up. Boosters are key, preferably one with MMT, we need that to make up for lack of lead.

Our cars (hi compression 350 10.25:1) required 98 octane minimum from the factory IIRC. Even though they altered how they rate the gas today vs back then, that's still like 95+ octane by modern standards. So we are out of luck, unless you detune your car, etc.

I have put 100 octane unleaded in my car at the track and it ran flawlessly.

 

Fun71 I usually still drive it even in the winter. The problem with e blend fuels is they suck up moisture and you end up with a layer of water in the fuel. From what i have read. I have had my car run with no issues on 6 month old fuel but for the most part if it's running I take it out any chance i get

 

Not always 100% reliable because of constant changes and mostly user-sourced information, but this is a good place to start on finding non-ethanol gas.

https://www.pure-gas.org/

 

In my area, there is no non-ethanol choice to be found. For the last 6 years, I have just been running 93 octane from whatever pump is convenient. The only issue that I have seen is that it evaporates faster, which in turn means pumping the gas before startup to put fuel back in the carb. No big deal so far.

 

x2

I found the same thing to be true about buying diesel for my truck. Whatever gasoline you buy it's best to get it from a hi volume gas station. The E10 I buy for my 96 I always buy at Sam's Club which is right off of I-35 in Edmond. The 100% gas I buy for my 71 I get from VP Racing Fuels which is at the intersection of two major boulevards in Edmond. It's best to avoid the little "mom & pop" gas stations with one or two pumps that are off the beaten path. The gas probably sits in their tanks for weeks if not longer.

 

Yeah, water absorption is what I was meaning when I said it may depend upon the geographic area. Here in the desert area where the humidity is low and it rarely rains would be very different from an area with high humidity, rain, condensation, etc.

This is really splitting hairs, but I'm not sure you'd end up with a layer of water. It would be like using dry gas or whatever it's called to get water out of your fuel system - the water would mix with the alcohol, which mixes with the fuel then it is all burned in the engine. But if you're in a damp area the fuel could absorb water due to the alcohol, then that watery fuel sitting in the tank and carb for an extended time could cause issues. I dunno, maybe the water could precipitate out under certain conditions (like cold temperatures) and end us as a layer on the bottom of the tank?

 

Fun71 from my understanding. Once thw moisture is in the fuel there is no getting it out. Even if you add more fuel. I belive itsncalled phase seperation. Indidnsome research on E blended fuels when I added efi to my Pontiac. Mainoy for reasons of getting the correct hoses and why etc etc. i learned alot.

 

The only way I know of to separate water from fuel is with a water separator. There's no need to run one on an Oldsmobile unless you have a 1978-1985 Oldsmobile diesel, or if you have a high-performance racing engine I suppose.

 

There is water separators but I think for the most part on gasoline engines its kind of an unlikely need. Even on a race engine. Although a water sepeartor will seperate it I think the octane rating is no longer the same once the chemical formulation is changed. I'm yetmto have issues on E blended fuels but there is alot of great info on the subject out there.