Fuel

[WigglesTheHoly]

I've been cruising the forums today and have noticed a few people with motor issues and people have mentioned 93 oc gas instead of 87. My question is what flavor of gas should we be running in our squares? Motors such as inline6's, 350s, 305s, 327s, 283s? I know that gas has changed a good deal in the past decade due to different mixes for cleaner exhaust and yada yada yada.

[Your41Plague12]

Whatever it was meant to run on from the factory, which is usually 87 octane. Try if you can to find gas without ethanol in it, as it will wear out components faster as well as drop fuel economy. The people (like me) than run 93 have more built motors with a high compression ratio.

[tucsonjwt]

I buy the cheapest gas available for my 83 C20 454 and have never had any fuel problems. When I tried premium gas it made no difference in performance or fuel economy.

[Goldfinger]

87 hasn't bothered mine at all.

[andrewmp6]

Too high of a octane can be a waste of money and hurt your mpg too.If it don't spark knock on 87 keep using it and not all gas is the same i stick to shell and bp.

[old Rusty C10]

I will only run 87 in mine and the cheapest brand i can get.. WAWA is usually the winner in that..I try to avoid small gas stations that have only one or two outlets

[78 Chevyrado]

I'm using 87 in mine too.

[2badgn]

Interesting, I always thought that 93 Octane would be better for the carburetor.

Years ago, I ran 93 and whenever my dad or I would put in Regular, the truck would knock.

I have since replaced the carb with an NOS Rochester Quadrajet and have only run 93 and it runs good.

Should I switch to 89 Plus for 2 tanks and then try 87 Regular?
Mine is a 1984 GMC 1 Ton 350.

I usually use Sunoco but I am open to using BP and Shell.
I wont go to a no name gas station.

[gofastbobby]

I run premium in my '76. I have ALOT of timing advance in it, and run a hot plug. in my dd, '05 expedition, I run 89. Whenever I can, I use Shell gas. I notice a fuel economy difference only when I go to certain truck stop style stations, like Loves.

[maskale]

octaine is not HP in a bottle and by itself has nothing to do with power, if u dont know wheather or not u should be using it, then u should probably be using 87

it wont make ur engine run cleaner.

[hotrod_991]

I run 87 with octane booster at each fill up. cheaper than just using 91 and keeps mine from knocking. I am right at the 10:1 cp line tho

[sethv]

I run 93, only because my timing is advanced quite a bit. I can retard it back to about stock and run 87 without a problem though.

[SCOTI]

Of the older trucks that I've owned, the older motors that were built when regular leaded fuel was available have a tendency to want higher octane 91-93 (if they're still original & still going).

I usually try lower grade fuel 1st to see what happens. If it 'runs-on' after shutting it off, I switch to the higher grade. Once it's rebuilt, you can run the cheap stuff if the engine combo is 'stock' or built for the lower octance if it's perf based.

My 68 w/the original 6cyl wanted 93.
My 74 w/its original 350 wanted 93.
My 89 dually did just fine on 87 grade.

[WigglesTheHoly]

my 78 is all original I've been running 87 but just wondered. It makes me think back to my 327 I had bored 30 over with a hot cam, I wonder if I should have been running something a bit richer.

[78 Big10 454]

I've run 87 octane in my '78 454 since Day 1 with no problems. By the way, don't get lulled into thinking that Shell (or any other company, for that matter) solely supplies their service stations only. I have a few close friends in the industry that have told me that oil companies sell to their competitors, ie, you could be buying BP gas at a Shell station and vice-versa. It's an industry-wide practice that was even featured on one of the news magazines on TV recently.

[1LowToy]

Yeah well ARCO has found a way to make their fuel really Suck. It almost killed my Mercedes. I had to stop ASAP to get some octane booster before it did.

Sure am glad they don't sponser any racing events, nobody would finish never mind win