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#1 |
IT Guy/ Father/ Chevy lover
Join Date: Feb 2010
Location: Hoisington, KS
Posts: 568
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Fuel
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.
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78 Chevy (Pictures) SOLD 79 Chevy LWB (pasture) 83 Chevy LWB (crushed rusted beyond repair) 02 TrailBlazer SOLD 03 VW Passat wagonSOLD 95 extended cab silveradoSOLD (still in family) 05 Crew Cab Silverado 5.3 (The Turd) WTB: 66 El camino ![]() Technology Specialist aspiring to be a gear head. ![]() |
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#2 |
Registered User
Join Date: Dec 2010
Location: Pittsburgh, PA
Posts: 1,009
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Re: Fuel
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.
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Steve Member of the Foot Pedal Club '83 Chevy K20: 6" Rough Country, 3" Performance Accessories BL, Bushwacker Cutouts, 38x15.50 Mickey Thompson Baja Claws, 350 HP 350 crate engine from Jegs, Turbo 400 ![]() |
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#3 |
Registered User
Join Date: Jul 2007
Location: Tucson, AZ
Posts: 3,188
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Re: Fuel
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.
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#4 |
Registered User
Join Date: May 2010
Location: laurel hill Fl
Posts: 645
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Re: Fuel
87 hasn't bothered mine at all.
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1985 C10 Custom Deluxe LWB 305/700r4 [ Goldfinger ] ![]() 1999 k3500 crew cab dually 6.5tdi/4l80e |
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#5 |
Registered User
Join Date: Jan 2009
Location: Louisville,Ky
Posts: 5,811
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Re: Fuel
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.
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#6 |
Robert Olson Transport
![]() Join Date: Oct 2002
Location: recent transplant to NC USA
Posts: 20,287
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Re: Fuel
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
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Bob 1951 International running on a squarebody chassis "If a man's worth is judged by the people he associates himself with, then i am the richest man in the world knowing some of the fine people of this board" http://67-72chevytrucks.com/vboard/a...t.php?f=25&a=9 (you can review the site rules here!) PM Me for your vehicle/parts hauling needs in the North East US or see my Facebook page Robert Olson Transport Live each day to the fullest.. you never know when fate is going to pull the rug out from under you... I hate cancer!! |
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#7 |
Account Suspended
Join Date: Dec 2007
Location: Unnapreciative, Trollville
Posts: 2,079
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Re: Fuel
I'm using 87 in mine too.
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#8 |
Registered User
Join Date: Nov 2009
Location: Yonkers, NY
Posts: 277
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Re: Fuel
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. |
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#9 |
Registered User
Join Date: Mar 2011
Location: Kalamazoo, MI
Posts: 120
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Re: Fuel
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.
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'76 C10 "BIG10" SWB 454/400 Mostly Stock. |
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#10 |
Registered User
Join Date: Jul 2011
Location: Houston, Tx
Posts: 159
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Re: Fuel
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. |
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#11 |
Registered User
Join Date: Jul 2009
Location: Thibodaux, LA
Posts: 479
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Re: Fuel
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
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"Buckle up I wanna try somethin!!" "of course it will hold!, I welded it!" 1977 c10 under knife for full rebuild, 5.3l 4l60e drive rain swap, replacement frame and green repaint |
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#12 |
Registered User
Join Date: May 2011
Location: Bradford, PA
Posts: 395
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Re: Fuel
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.
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1981
![]() 305 ci | TH350 | NP208 | 60k miles |
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#13 |
Registered User
Join Date: Apr 2001
Location: DALLAS,TX
Posts: 21,963
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Re: Fuel
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.
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67SWB-B.B.RetroRod 64SWB-Recycle 89CCDually-Driver/Tow Truck 99CCSWB Driver All Fleetsides @rattlecankustoms in IG Building a small, high rpm engine with the perfect bore, stroke and rod ratio is very impressive. It's like a highly skilled Morrocan sword fighter with a Damascus Steel Scimitar..... Cubic inches is like Indiana Jones with a cheap pistol. |
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#14 |
IT Guy/ Father/ Chevy lover
Join Date: Feb 2010
Location: Hoisington, KS
Posts: 568
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Re: Fuel
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 Chevy (Pictures) SOLD 79 Chevy LWB (pasture) 83 Chevy LWB (crushed rusted beyond repair) 02 TrailBlazer SOLD 03 VW Passat wagonSOLD 95 extended cab silveradoSOLD (still in family) 05 Crew Cab Silverado 5.3 (The Turd) WTB: 66 El camino ![]() Technology Specialist aspiring to be a gear head. ![]() |
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#15 |
78 Big10 454
![]() Join Date: Jul 2008
Location: Pismo Beach, CA
Posts: 838
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Re: Fuel
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.
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1978 Chevy SWB C-10 2WD 454/400 |
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#16 |
Registered User
Join Date: Nov 2009
Location: Sonora California
Posts: 860
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Re: Fuel
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 |
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