Fuel recommendation a 1950

[Ash84]

I'm just getting into the classic car world and learning a lot already. I got 1950 Plymouth delux and was wondering with modern day fuel what kind should I be running. I have regular fuel in it not just to get it running. I know this should off been first thing I ask be fore I put any thing it but like I said I'm learning, and it's only like 3 gallons. I was thinking a higher tes fuel would better but not sure how that would react with the regular fule I got running through the lines now and how the engine would expect it. It has 96,000 miles on original engine.

[Andydodge]

Ideally any fuel that doesn't contain Ethanol would be my recommendation...when I had my 41 Plymouth Coupe, it had the standard 1941 201 cube engine and I used to use the "standard " "91 " octane rated fuel but did not put any that had ethanol mixed in......at least to my knowledge that is............now with my 318 Poly V8 1940 Dodge I only use 98 octane..........BTW...........Welcome aboard from Oztralia.......Andy Douglas

[Doug&Deb]

Ethanol can cause problems with the fuel system. I recommend rebuilding the carb. Make sure the kit contains ethanol resistant parts. I’d also replace the fuel pump with one that has an ethanol resistant diaphragm. I run 89 octane in my 52 Coronet and have had no issues.

[Sniper]

I just go to the local Shell station and fill up with regular, which may contain up to 10% ethanol.

 

Runs just fine on that, but I drive my car all the time.

[wagoneer]

My Chrysler gets better gas than I ever put into my daily drivers; the local shell stations sell 89 ethanol free and 93 ethanol free.

Normally I never buy anything above 87, but she runs real nice on 93.

[1949 Wraith]

I run what ever is on sale. 6.5:1 compression,  just drive it.

[Sam Buchanan]

I run the cheapest 87 that has been contaminated with ethanol and my '48 P15 is happy.   

 

More importantly I usually only put in 4-5 gallons to keep the gas fresher.  There are no problems with mixing different octanes in the same tank.

Edited August 22, 2021 by Sam Buchanan

[JerseyHarold]

Just a reminder that  flathead sixes do NOT need leaded gasoline because they have hardened valve seats.  Mopar was way ahead of its time...

[Ash84]

3 hours ago, Doug&Deb said:

Ethanol can cause problems with the fuel system. I recommend rebuilding the carb. Make sure the kit contains ethanol resistant parts. I’d also replace the fuel pump with one that has an ethanol resistant diaphragm. I run 89 octane in my 52 Coronet and have had no issues.

I figure taking off carb would be a good idea I will check and make sure it's ethanol resistant parts that's a good point. I have got three different small engines from auctions and cards were destroyed from the fuel. 

[Ash84]

Well looks like any fule is my options thank for the info every one. I kinda figured the engine could take what ever, I know the guy that had the car before and is not a very preventative maintenance kinda person lol. It's runs pretty good for sitting for 30 years 

[capt den]

i use 87 non ethanol mostly, but my 80,000 mile 265 will run just fine on regular. i will only buy gas that is tier 1. i also use techron occasionally to treat the system. i am not a big believer in additives, but i have seen the innards of systems that use that and they are clean. i have the glass bowl on my pump so it is easy to see that the tank is in good shape.    capt den

[Dan Hiebert]

I've always used the lowest octane fuels available.  Being a tad frugal has something to do with it, but our engines were engineered to run on lower octane fuels in the first place.  When we lived in "higher" elevations (west Texas, NM) the low end was 89 octane due to the altitude, since moving into elevations of less than 1,000 feet, the low end octane has been 87.  Yes, they will run somewhat better on higher octanes, but the octane rating is more to prevent knocking with higher compression, not provide more power.  Higher octane becomes pointless at some stage (There has been past discussion herein about octane, good read if you can find it).  Ethanol can be hard on seals and such that were not designed for it.  That said, I haven't messed with my fuel system components since well before ethanol became commonplace, and haven't had any problems with it at all.  (Probably just jinxed myself.)  I always add fuel conditioner/stabilizer to lessen the effects of ethanol and keep the system cleaner. 

[belvedere]

ethanol-free, minimum 87 octane

[allbizz49]

I'm with Sniper and Wraith. I run 87 with whatever percentage of corn they put in. But I drive my car almost every day so the fuel never has a chance to get old. Every now and again I'll toss a little seafoam or marvel mystery oil in the tank just because. Figure a little extra cleaning or lube can't hurt. If you are going to pull the carb apart, a drop of oil or two on the accelerator pump leather helps keep it pumping. Good luck and enjoy your ride.

Edited August 23, 2021 by allbizz49