Ok would using premium grade over regular grade improve a 1998 GMC 5.7's towing power and mileage. I had heard that by using premium it allows the computer to advance the timing more and thus increase the motor performance. Is this true??
Regular versues Premium
- Thread starter wolfden
- Start date
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Swims350
I'm Awesome
I would highly doubt it raises or advances the timing more, BUT it would lower it LESS, due to spark knock or detonation. The spark knock could be caused by low octane/grade fuel and could be alot more with the reg. unlead crap then with prem. if this is the case then less sprak knock due to running the prem. would result in fewer number of times the computer had to retard the timing due to spark knock.
Advance more I doubt, stop retarding, YES.
As for a vehicle and improving mileage, my old man swears it gets you better mileage, in the wife's 2k monte carlo didn't see any increase in mileage compared to reg. unleaded.
On my four wheeler, I notice a HUGE difference over prem. fuel then reg. When I use prem. it runs better, smoother, feels like alot more torque and power. I can take hills in 2wd high in 2nd or 3 with prem. that I would have to use 1st of even low on reg. fuel to climb.
Advance more I doubt, stop retarding, YES.
As for a vehicle and improving mileage, my old man swears it gets you better mileage, in the wife's 2k monte carlo didn't see any increase in mileage compared to reg. unleaded.
On my four wheeler, I notice a HUGE difference over prem. fuel then reg. When I use prem. it runs better, smoother, feels like alot more torque and power. I can take hills in 2wd high in 2nd or 3 with prem. that I would have to use 1st of even low on reg. fuel to climb.
454cid
Sooper Pooper
Our trucks are designed to run regular. Unless you're engine is modified (more than CAI and other similar bolt ons) all you need is regular. GM does spec premium for some vehicles, like the Vette. Some older cars run it too, like my 69 Buick...... it has a 10.25:1 compression ratio.
FastOrange
OBSless
Stockish trucks only need regular.
kinda....allow the computer to advance the timing? as in an automatic thing, nope.....allow YOU to advance the timing IN the computer via tuning? yup. higher octane fuel burns slower, and therefore resists detonation, which allows for higher spark advance, but its not an automatic thing, it won't just give you more power without you, or a tuner of some sort going in and changing the computer parameters manually.
its also useful to run higher octane in highly modified engines with higher compression ratios, forced induction, or other situations that may have a higher possibility of detonation.
for a stock or stockish engine regular is all you need. like has already been mentioned.
Fobroader
I'm Awesome
I run a tank of high test every 3-4 tanks just to clean out the combustion chambers....trucks not any faster tho.....
Some engines need it stock, stock '90s pick up trucks? Nope.
If it required premium and you run regular, you'll see a big difference between the two. Accidentally put 87 in the STS once. Ran fine, but lost a lot of power. I went to the next gas station a filled up with premium.
But if it requires regular and you put in premium, you won't notice much at all, if any difference.
If it required premium and you run regular, you'll see a big difference between the two. Accidentally put 87 in the STS once. Ran fine, but lost a lot of power. I went to the next gas station a filled up with premium.
But if it requires regular and you put in premium, you won't notice much at all, if any difference.
My .02, I run 93 in the 88' at all times. My stock 99 Burb ran fine on 87 and saw no benefits with any higher grades. On 87, the 88'(crate 350HO, cam,intake,etc with stock bottom end/heads) seemed to run rougher and hesitate a lot more frequently. Running 93, I notice she's smooth as glass at idle, better responsiveness off the line and less hesitation overall. In no way have I seen better mileage. Even if I did, it would have to make up for the higher cost of 93 to really make it worth it.
Fobroader
I'm Awesome
X2 That ^^^^^ My V6 Altima runs like ass when Ive had no option but run 87octane, on 93 or 94, wooohooo. The truck has no cares what sort of dino juice it gets.
