hi , just picked up a stock '74 valiant with a 225 slant 6 , auto . electronic ignition . 144,000 miles . bought it from a dealer and they don't know what is in it gas wise . i was wondering what should i use ? regular 87 . plus 89 , or premium 93 ? i am on east coast in NJ . any recommendations are appreciated . obviously i would like to use the cheapest gas , but don't mind paying extra if its worth it . thanks
stock slant six , which grade of gas should i use ?
- Thread starter moparjon
- Start date
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TrailBeast
AKA Mopars4us on Youtube
One thing about that I would like to mention is that I run 87 in my 318 most of the time, but if I run 91 and bring the timing up to accommodate it, I get more miles out of the 91 than with the 87.
So the 91 cost more and I get less gas for the money, but I get more miles to the gallon, so it's a balancing act.
You do have to watch the prices and realize when that gets too far out of balance prices wise.
So the 91 cost more and I get less gas for the money, but I get more miles to the gallon, so it's a balancing act.
You do have to watch the prices and realize when that gets too far out of balance prices wise.
TylerW
Well-Known Member
87 should be fine, but keep your ear tuned to listen for "pinging", otherwise called spark knock or detonation. That's hard on pistons and rod bearings so if it does that on 87 you may need to run a higher octane.
roadrunnerh
Well-Known Member
87 is what I run in my 75 Scamp \6
bigus1949
Well-Known Member
i switch between 87 and 93 every other tank. That seems to work well for me and sassy.
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