Gas - The 1947 - Present Chevrolet & GMC Truck Message Board Network

cliffsta · 09-24-2004, 12:09 AM

I must be doing better in my conservationism (or feathering of the throttle). I got 12.9 MPG on my last tank of gas, about 65/35 in favor of city driving. With a misadjusted, ancient original 2 barrel, i think thats OK.

I usually get between 10-12.
So being the broke, unemployed high school student i am, i managed to bum a check off my mom so i sprang for premium (89 octane) gas. Haven't drivin any farther than 300 feet from my house to the gas station on the Good Stuff, so i haven't noticed a diff. You guys run 89 or 93, or do you keep it real on 87 like i usually do?
PS i AM looking for a job, supposed to get hired by K Mart this week
wish me luck

1987SierraClassic · 09-24-2004, 12:25 AM

Clifsta - First of all - good luck! I'm waiting to hear on a new job myself! Second, I get almost 15MPG with my 350 powered Suburban with 33" tires and a 700R4 automatic, of course the fuel injection makes a huge difference! I run 93 in both my rigs. The Suburban runs terrible on 87. I notice slightly better mileage on the good stuff. When I bought my Suburban, I got 11 MPG. I put Amsoil 0W-30 in the crankcase and it went up to about 12.5. I fixed a few vacuum leaks and put Amsoil ATF in the transmission and now I hover between 14.5 and 15 around town. Not much difference on highway mileage with the 'Burb. My '87 Pickup with a 4.3L v6 and manual trans gets about 17. It's never had anything but super...still going at 185,000.
If you don't notice a difference in the way it runs, stay with the 87. Mine pings like crazy on 87....

Russell · 09-24-2004, 12:39 AM

The only reason why you'd ever really need to upgrade to a higher octane fuel is if you are running a fuel injection setup that bases the timing on the reading the knock sensor provides, or if you are pinging something nasty running on 87. Otherwise, its really not worth your money.

The only difference between an 87 octane, or 92 octane fuel is the amount of potential energy contained in it, its not enough of a difference for you to feel a noticable increase in power, but it is enough that it won't detonate like a diesel motor before the plug goes off due to temperature and pressure.

screwballl · 09-24-2004, 02:51 AM

with my 76 GMC i run 87 usually but when i have used 93 for a few tanks it doesnt make any difference on fuel economy, power, anything. I have a stock tired 350 with a new Edelbrock 600cfm and i noticed since the carb switch, it runs better with 87 than 93 including better gas economy, power etc...
it all depends on the vehicle, how it was run before, what it has run on for the past decade or two. Most vehicles with a true carb tend to run better on 87 due to the previous need for lead gas but fuel injected tends to run better with premium. Again it all depends on what it has run on for its life. Get it used to 87 new and you will never know the difference but use premium for several years with a new vehicle or engine and you will notice a big difference if you use regular down the road...

**76sierraclassic** · 09-24-2004, 05:23 AM

My 76 has a very tired stock 350/350/4bbl (141,000 miles) and I run 93 octane in it. Honestly, I've never tried the lower grade gasolines in this truck, so they might do ok, but as long as I can afford it, I'll go ahead and burn the higher octane. I just think it burns cleaner, but that could just be my imagination. The one time I checked the mileage on the highway (short road trip of about 160 miles at 55-65 MPH) it was getting just under 15 MPG. That was taking it very easy on it. I don't really check it that much because it's too depressing. Of course, that's only about 2 MPG less than I get from my 2000 Nissan Crew Cab with 3.3L V6 with automatic transmission which I drive to work 80+ miles round trip each day.

Mike

cliffsta · 09-24-2004, 09:28 PM

Well. this morning when i fired ol red up to head to school, it ran better cold. It didn't chug and try to flood when i gave it gas, and to warm it up i had to give it far less throttle to run clean. Didn't notice much difference to and from school today, other than it idled a little better. My dad said the timing has always been kinda off on it since he bought it new, and if he ran 89 or 93 it didn't ping in the heat. But since changing over to Max Life oil, it doesn't ping at all anymores. he said it was nice to run 89 b/c he felt a noticeable difference. I figure ima go crusing around wherever as i usually do on fridays after football game, so ill give a good report then.

**swervin ervin** · 09-25-2004, 02:30 AM

It's a total waste of good money to use 93 octane if it's not needed. Believe me, if you have a stock, low compression engine, it's not needed.

Higher octane fuel ignites slower than low octane. This is the sole reason it stops pinging and pre-ignition. The lower the octane you can run, the better power and economy you will get. If you are having pinging problems, you need to address the problem with something besides 93 octane. If you are running a high compression engine, you probably don't have any choice. The absolute best thing you can do to any engine is get the timing dialed in properly. Don't mask bad timing with a high priced fuel.

Of course, it's your money. Spend it where you like.

screwballl · 09-25-2004, 02:43 AM

i get the same gas mileage in my truck that the wife does in here crappy 95 Nissan Pathfinder

cliffsta · 09-25-2004, 05:19 PM

lol. yeah i definately noticed a change for the better last night driving around. It ran much smoother and cleaner. It doesn't run bad on 87, but it just runs better on 89. it was raining/wet last night so i didn't dog on it, i just tried to keep it between the navigational beacons to get to the party

Not too hard since the party was about 1/4 mile up the street.

71-longbed · 09-26-2004, 08:27 AM

why even drive a 1/4 mile ??? your feet injured or something

screwballl · 09-26-2004, 04:48 PM

also watch it in certain areas of the midwest or wherever they use Ethanol in the midgrade, this can burn up fuel injectors and clog your carb jets... it allows rust to form on the injectors/jets and burns them up usually in 40,000 miles constant use or 80-100K miles occasional use...
this happened to my mom and her old 90 Lumina, she always used 89/Mid and they needed to be replaced after 45K miles. then when she got the 93 Grand Prix same thing... i mentioned to her many times through the years so now with her 2000 Malibu she hasnt used it once and is doing great around 55K miles

cliffsta · 09-26-2004, 06:26 PM

Quote:

Originally Posted by 71-longbed

why even drive a 1/4 mile ??? your feet injured or something

If you read my post you would see IT WAS RAINING

Anywho, after driving round this weekend, i definately like 89 over 87. I think im gonna stick with 89. Thanks 4 the imput from all.

RockHQ · 09-26-2004, 06:34 PM

Quote:

Originally Posted by Russell

it won't detonate like a diesel motor

DIESELS DO NOT DETONATE.

09-24-2004, 12:09 AM	#1
cliffsta Stepsides RULE Join Date: Jul 2004 Location: Pineville, LA Posts: 1,921	Gas I must be doing better in my conservationism (or feathering of the throttle). I got 12.9 MPG on my last tank of gas, about 65/35 in favor of city driving. With a misadjusted, ancient original 2 barrel, i think thats OK. I usually get between 10-12. So being the broke, unemployed high school student i am, i managed to bum a check off my mom so i sprang for premium (89 octane) gas. Haven't drivin any farther than 300 feet from my house to the gas station on the Good Stuff, so i haven't noticed a diff. You guys run 89 or 93, or do you keep it real on 87 like i usually do? PS i AM looking for a job, supposed to get hired by K Mart this week wish me luck __________________ 1981 Chevy C10 Custom Deluxe Stepside 350 V8, headers, side exhausts, 3-speed auto SOLD 1980 Chevy C10 Custum Deluxe Stepside 305 V8, Edelbrock Performer Intake, Edelbrock 1406 600CFM 4-barrel, TH350C. Bent rod. SOLD 1984 GMC Sierra Classic Longbed 6.2L Diesel SOLD 2009 Kawasaki KLX-250S too many mods for this signature 1999 Honda Accord EX 4-cylinder, 17" Motegi Wheels 215/45/17 Sumitomo tires, Tein S-Tech lowering springs, KYB GR2 shocks, Acura TL 20mm rear swaybar, debadged, blackhoused headlights, Short-Ram Intake Cardomain of the Accord

09-24-2004, 12:39 AM	#3
Russell Professional Grade Join Date: May 2003 Location: Fort McMurray, Alberta Posts: 7,915	The only reason why you'd ever really need to upgrade to a higher octane fuel is if you are running a fuel injection setup that bases the timing on the reading the knock sensor provides, or if you are pinging something nasty running on 87. Otherwise, its really not worth your money. The only difference between an 87 octane, or 92 octane fuel is the amount of potential energy contained in it, its not enough of a difference for you to feel a noticable increase in power, but it is enough that it won't detonate like a diesel motor before the plug goes off due to temperature and pressure. __________________ 1995 Chevrolet 2 Door Tahoe (6.6L LBZ Duramax / ZF6 / NP241 with 1 ton solid axle swap)

09-24-2004, 02:51 AM	#4
screwballl Tonawanda 454 Join Date: Mar 2004 Location: Liquid Sunshine State Posts: 2,755	with my 76 GMC i run 87 usually but when i have used 93 for a few tanks it doesnt make any difference on fuel economy, power, anything. I have a stock tired 350 with a new Edelbrock 600cfm and i noticed since the carb switch, it runs better with 87 than 93 including better gas economy, power etc... it all depends on the vehicle, how it was run before, what it has run on for the past decade or two. Most vehicles with a true carb tend to run better on 87 due to the previous need for lead gas but fuel injected tends to run better with premium. Again it all depends on what it has run on for its life. Get it used to 87 new and you will never know the difference but use premium for several years with a new vehicle or engine and you will notice a big difference if you use regular down the road... __________________ 91 Chevy Suburban Tonawanda 454 R2500 - SOLD!!! 04 Dodge Durango 5.7L Hemi 2WD, 24K miles (as of July 2011) In the past 30 years about 90% of Fords are still on the road, the other 10% made it home. -------------------

09-24-2004, 09:28 PM	#6
cliffsta Stepsides RULE Join Date: Jul 2004 Location: Pineville, LA Posts: 1,921	Well. this morning when i fired ol red up to head to school, it ran better cold. It didn't chug and try to flood when i gave it gas, and to warm it up i had to give it far less throttle to run clean. Didn't notice much difference to and from school today, other than it idled a little better. My dad said the timing has always been kinda off on it since he bought it new, and if he ran 89 or 93 it didn't ping in the heat. But since changing over to Max Life oil, it doesn't ping at all anymores. he said it was nice to run 89 b/c he felt a noticeable difference. I figure ima go crusing around wherever as i usually do on fridays after football game, so ill give a good report then. __________________ 1981 Chevy C10 Custom Deluxe Stepside 350 V8, headers, side exhausts, 3-speed auto SOLD 1980 Chevy C10 Custum Deluxe Stepside 305 V8, Edelbrock Performer Intake, Edelbrock 1406 600CFM 4-barrel, TH350C. Bent rod. SOLD 1984 GMC Sierra Classic Longbed 6.2L Diesel SOLD 2009 Kawasaki KLX-250S too many mods for this signature 1999 Honda Accord EX 4-cylinder, 17" Motegi Wheels 215/45/17 Sumitomo tires, Tein S-Tech lowering springs, KYB GR2 shocks, Acura TL 20mm rear swaybar, debadged, blackhoused headlights, Short-Ram Intake Cardomain of the Accord

09-25-2004, 02:30 AM	#7
swervin ervin You get what you pay for Join Date: Dec 1999 Location: Cherryville, NC Posts: 4,798	It's a total waste of good money to use 93 octane if it's not needed. Believe me, if you have a stock, low compression engine, it's not needed. Higher octane fuel ignites slower than low octane. This is the sole reason it stops pinging and pre-ignition. The lower the octane you can run, the better power and economy you will get. If you are having pinging problems, you need to address the problem with something besides 93 octane. If you are running a high compression engine, you probably don't have any choice. The absolute best thing you can do to any engine is get the timing dialed in properly. Don't mask bad timing with a high priced fuel. Of course, it's your money. Spend it where you like. __________________ Mike 1985 Chevy C-10

09-24-2004, 12:25 AM	#2
1987SierraClassic Registered User Join Date: Sep 2004 Location: Buxton, ME Posts: 91	Clifsta - First of all - good luck! I'm waiting to hear on a new job myself! Second, I get almost 15MPG with my 350 powered Suburban with 33" tires and a 700R4 automatic, of course the fuel injection makes a huge difference! I run 93 in both my rigs. The Suburban runs terrible on 87. I notice slightly better mileage on the good stuff. When I bought my Suburban, I got 11 MPG. I put Amsoil 0W-30 in the crankcase and it went up to about 12.5. I fixed a few vacuum leaks and put Amsoil ATF in the transmission and now I hover between 14.5 and 15 around town. Not much difference on highway mileage with the 'Burb. My '87 Pickup with a 4.3L v6 and manual trans gets about 17. It's never had anything but super...still going at 185,000. If you don't notice a difference in the way it runs, stay with the 87. Mine pings like crazy on 87....

09-24-2004, 05:23 AM	#5
76sierraclassic Senior Member Join Date: Feb 2004 Location: White Hall, AR Posts: 316	My 76 has a very tired stock 350/350/4bbl (141,000 miles) and I run 93 octane in it. Honestly, I've never tried the lower grade gasolines in this truck, so they might do ok, but as long as I can afford it, I'll go ahead and burn the higher octane. I just think it burns cleaner, but that could just be my imagination. The one time I checked the mileage on the highway (short road trip of about 160 miles at 55-65 MPH) it was getting just under 15 MPG. That was taking it very easy on it. I don't really check it that much because it's too depressing. Of course, that's only about 2 MPG less than I get from my 2000 Nissan Crew Cab with 3.3L V6 with automatic transmission which I drive to work 80+ miles round trip each day. Mike

09-25-2004, 02:43 AM	#8
screwballl Tonawanda 454 Join Date: Mar 2004 Location: Liquid Sunshine State Posts: 2,755	i get the same gas mileage in my truck that the wife does in here crappy 95 Nissan Pathfinder __________________ 91 Chevy Suburban Tonawanda 454 R2500 - SOLD!!! 04 Dodge Durango 5.7L Hemi 2WD, 24K miles (as of July 2011) In the past 30 years about 90% of Fords are still on the road, the other 10% made it home. -------------------

09-25-2004, 05:19 PM	#9
cliffsta Stepsides RULE Join Date: Jul 2004 Location: Pineville, LA Posts: 1,921	lol. yeah i definately noticed a change for the better last night driving around. It ran much smoother and cleaner. It doesn't run bad on 87, but it just runs better on 89. it was raining/wet last night so i didn't dog on it, i just tried to keep it between the navigational beacons to get to the party Not too hard since the party was about 1/4 mile up the street. __________________ 1981 Chevy C10 Custom Deluxe Stepside 350 V8, headers, side exhausts, 3-speed auto SOLD 1980 Chevy C10 Custum Deluxe Stepside 305 V8, Edelbrock Performer Intake, Edelbrock 1406 600CFM 4-barrel, TH350C. Bent rod. SOLD 1984 GMC Sierra Classic Longbed 6.2L Diesel SOLD 2009 Kawasaki KLX-250S too many mods for this signature 1999 Honda Accord EX 4-cylinder, 17" Motegi Wheels 215/45/17 Sumitomo tires, Tein S-Tech lowering springs, KYB GR2 shocks, Acura TL 20mm rear swaybar, debadged, blackhoused headlights, Short-Ram Intake Cardomain of the Accord

09-26-2004, 08:27 AM	#10
71-longbed Its Magically Delicious Join Date: Jan 2003 Location: oregon Posts: 2,398	why even drive a 1/4 mile ??? your feet injured or something __________________ 71 C10 LWB 350sbc -TH350 12 bolt 3.42 Posi Of all my favorite things to do, The utmost is to have a brew. My love grows for my foamy friend, with each thirst-quenching elbow bend. Beer so frosty, smooth, and cold it's paradise pure liquid gold. Yes beer means many things to me that's all for now cus I gotta pee.

09-26-2004, 04:48 PM	#11
screwballl Tonawanda 454 Join Date: Mar 2004 Location: Liquid Sunshine State Posts: 2,755	also watch it in certain areas of the midwest or wherever they use Ethanol in the midgrade, this can burn up fuel injectors and clog your carb jets... it allows rust to form on the injectors/jets and burns them up usually in 40,000 miles constant use or 80-100K miles occasional use... this happened to my mom and her old 90 Lumina, she always used 89/Mid and they needed to be replaced after 45K miles. then when she got the 93 Grand Prix same thing... i mentioned to her many times through the years so now with her 2000 Malibu she hasnt used it once and is doing great around 55K miles __________________ 91 Chevy Suburban Tonawanda 454 R2500 - SOLD!!! 04 Dodge Durango 5.7L Hemi 2WD, 24K miles (as of July 2011) In the past 30 years about 90% of Fords are still on the road, the other 10% made it home. -------------------



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