Anyone think running Premium gas makes a differance in milage?

[TheGryme]

Just wondering.....
I drive at least 120 miles a day....across open roads....little stopping. Setting my cruze at all of 61......or if I'm feeling daring.....63mph, I get about 18 MPG running on the "A" map (UNICHIP) on regular gas.
I have yet to hear this engine ping....(I don't even know what this one sounds like pinging! ) so I wonder what effect if any higher octane gasola might produce......milage wise.
I have always equated milage with power....an underpowered '80's era truck with a 318CI engine would get about 12 MPG but the same truck with a 440 would get 15. I know 'cause I used to do these swaps. I always figured the 318's were working too much at wide open throttle to move the truck and the 440 had way more power on tap and didn't have to be ran at WOT.
So maybe higher octane gas will produce more power and the truck can be ran at a lesser throttle setting and get the same MPH on less gas?

[KLS]

Very unlikely that you will have a lower cost per mile with high octane gas. That's what really counts...fuel cost per mile, not miles per gallon nor cost per gallon.

You will never hear ping unless the knock sensors or other electronic parts fail. Some engines, not ours, build up carbon in the combuston chambers and ping when the red hot carbon ignites the fuel charge before the spark fires.


Ken

[2btundra]

Just the opposite for me. I've run 87, 89, and 93 in my '05 V8 Access Cab at different times. The lower the octane, the better the mileage. I can get 35-40 more miles on a tank of 87 as opposed to 93.

[cubic22]

Gas is gas is gas...unless..its ~GAS~

Clean throttle body, good spark plugs, clean air filter, and if you drive that much go ahead and spring for Nitrogen in the tires vs o2

[djw29]

Higher Octane fuels are more resistant to pre-ignition. Meaning that the fuel is less volatile or slower burning than low octane fuel. Only engines with high compression ratios need higher octane slower burning fuel because the higher the compression ratio, more heat is generated, which preignites fuel (pinging)unless an an additive is used to slow the burn. On some motors pinging can be very damaging. This is why supercharged rigs run premium, a greater volume of air is crammed into the cyllinder which creates more heat in the compression stroke and thus preignition of the fuel unless you use higher octane gas. So if your engine doesn't require premium, don't use it. In a lower compression motor it actually makes less power and produces more pollutants out the tailpipe than the lower rated fuel.

[S-Man]

What about using synthetic oil? i heard on tv that synthetic oil, although more expensive, will give you better gas mileage...probably not mileage worth the increased cost of syn oil, but i'd still like to know.

[TheGryme]

Originally Posted by djw29

Higher Octane fuels are more resistant to pre-ignition. Meaning that the fuel is less volatile or slower burning than low octane fuel. Only engines with high compression ratios need higher octane slower burning fuel because the higher the compression ratio, more heat is generated, which preignites fuel (pinging)unless an an additive is used to slow the burn. On some motors pinging can be very damaging. This is why supercharged rigs run premium, a greater volume of air is crammed into the cyllinder which creates more heat in the compression stroke and thus preignition of the fuel unless you use higher octane gas. So if your engine doesn't require premium, don't use it. In a lower compression motor it actually makes less power and produces more pollutants out the tailpipe than the lower rated fuel.

Thats interesting....I knew the info about pressures / heat and pinging...and damage caused (ask me about my $7K 3.0 engine someday ) I read a post in here a while back from a guy that just got a custom tune on his UNICHIP and was telling of special listening devices the shop used during the tune/ dyno to "listen" for ping. I'd like to know more about the tool used.
My truck seems to run the same (good ) on any gas......so far.
But I'm always looking for an edge in the gas milage dep't.

[supritdeol]

Originally Posted by cubic22

Gas is gas is gas...unless..its ~GAS~

Clean throttle body, good spark plugs, clean air filter, and if you drive that much go ahead and spring for Nitrogen in the tires vs o2

Nitrogen in tires makes no difference in MPG's. N2 gas is used my some shops because it stays in the tire longer than oxygen.

[dannozrx]

It probably wouldn't make a difference unless you also can find a chip that is programmed to work with the higher octane gas. I had 95 Chevy that I ran 92 octane for a few weeks, thinking better mileage, that got the same mileage and began stalling at times. The tech at the dealer found out what I was running for gas and told me to go back to 87 cause that is what the chip was programmed for.

[Crx722]

I use 85 in montana and dont notice any different from 91 at home

[cubic22]

Originally Posted by supritdeol

Nitrogen in tires makes no difference in MPG's. N2 gas is used my some shops because it stays in the tire longer than oxygen.

Correct it does not leave the rubber as quickly, does not eat away at the inner lining, and does not heat up as fast so you can keep the psi level more consistant...and I always thought keeping your psi level constant is a good way to conserve gas.

[student's tundra]

Originally Posted by supritdeol

Nitrogen in tires makes no difference in MPG's. N2 gas is used my some shops because it stays in the tire longer than oxygen.

Correct. We have been using Nitrogen in our customers cars for a year or so now. I believe that the molecules in Nitrogen are seperated more than oxygen. Thus allowing for more resistance to contracting and expanding with the daily elements. This is why Nitrogen will not escape as fast as oxygen in automotive tires. In addition, I have been told that it is supposedly saver in terms of tire blowout, can confirm this however. Just what I have picked up .

[KLS]

Originally Posted by Crx722

I use 85 in montana and dont notice any different from 91 at home

Modern engine control systems work best at every altitude with the fuel the engine was designed to run. This would be 87 even in the Rockies. 85 is the fuel of choice for an old, carbureted engine designed for low octane gas and run at high elevations. If you carefully measured engine performance, you'd get better performance with 87 over 85, even in Bozeman. (I use 85 in the Rockies...runs OK and is cheaper. I haven't tested to see which gives the lowest fuel cost per mile.)


Ken

[fcatwo]

I question whether there are any absolute rules on the "octane" thing. We had a 2002 Honda Odyssey minivan that the owners manual specified 87 octane but the towing section of the manual said premium fuel would provide better performance while towing. My trials were far from scientific but it seemed to hold transmission lock-up longer with premium which could provide a slight fuel economy advantage because of reduced engine revolutions per mile while towing -- but then, who knows. I often use premium in the Tundra and I think it runs quieter, has more power and my wife is less crabby than when I run 87 :-). I see buying premium as money well spent. Also, since many stations have kept the same 10 cent spread between fuel grades, $3.20 for premium is only 7% more than $3.00 for regular while $1.20 was 20% more than $1.00 for regular. It's a relative bargain now.

Frank