Premium vs. Regular Gas Mileage

[BASS]

Ok, for my beater car, I am debating whether to continue to use premium gas vs regular gas. Ive noticed that Ive been getting much better gas mileage using premium gas vs regular gas for some reason..Is it because the premium gas burns slower??

 

[no-nos]

the reason you've been getting better gas milage with premium is because the fuel is less volatile and requires more heat input before it begins to ignite.
A fuel with a higher AKI actually burns more SLOWLY than fuel with a lower AKI. (anti-knock index -- also known as "octane rating )

 

[TURBOPOWERED68]

not trying to be funny
but does it burn $.20 slower?

 

[klrv6]

If the car calls for premium, I'd say the timing tables or compression require it. If you dump regular in there it's going to knock. The computer will combat this knock with pulling timing, dumping in more fuel or both. Then you will use more gas with regular. I try not to run anything less than 89 and get pretty good mileage.

 

[BlackMetal]

Uhhhh fuel grade doesn't affect mileage.

 

[cool 84]

Octane most definately affects gas mileage. On a TR, it probably makes no difference with an 8.0:1 compression ratio. With my TL and it's 11.0:1 ratio, it gets enough better mileage on 91 to warrant the extra price. It's only $1.50 more per fillup and I get 3-5mpg better mileage. My car is so detonation happy and octane hungry that I get better mileage with a mix of 100 unleaded and 91 than straight 91. I used to do the exact same 260 mile trip twice a week for a year and I kept very close tabs on mileage.

 

[Pronto]

I definately get better gas mileage with premium than low octane in my 04 Maxima (calls for premium). I've checked it several times to make sure.

 

[klrv6]

The ECM retards (takes away power) when it hears knock. Do things to combat this and your car will get better mpgs. I have recently done some work on my suburban to enhance the mileage. Most of my time was spent on timing tables up to the point of detonation. It was worth the effort, with 89 in the tank, it knocks down 25mpg @ 80mph. Not too bad for taking advantage of timing.

 

[notacarlo]

Premium burns more "completely" than regular. So you use all of the injected fuel to make the power to get the car moving. With regular you might waste a little to get moving.

 

[BASS]

Thats the thing, this is for my beater car (regular, non-v-tec integra) that just calls for regular gas. Ive also noticed the same thing with my other beater cars that require regular gas only...

 

[GNBRETT]

The ECM retards (takes away power) when it hears knock. Do things to combat this and your car will get better mpgs. I have recently done some work on my suburban to enhance the mileage. Most of my time was spent on timing tables up to the point of detonation. It was worth the effort, with 89 in the tank, it knocks down 25mpg @ 80mph. Not too bad for taking advantage of timing.

You get 25 mpg in a Suburban at 80 mph? I find that hard to believe. It's more like 12 mpg. My Honda Accord gets about 25-28 mpg.

 

[JOHNDEEREGN]

You get 25 mpg in a Suburban at 80 mph? I find that hard to believe. It's more like 12 mpg. My Honda Accord gets about 25-28 mpg.

My 04 Durango Limited with a Hemi AWD gets 21 MPG @ 70 on the HWY. Oh yeah.... On Premium

 

[klrv6]

You get 25 mpg in a Suburban at 80 mph? I find that hard to believe. It's more like 12 mpg. My Honda Accord gets about 25-28 mpg.

Nope, it's true. even going up slight grades at that speed. The 2WD is what keeps it from getting the mileage of the "other" suvs. I got an awesome deal on Jet DST and bumped the timing up four degrees at cruise speeds/loads as autotap wasn't reporting any knock. This allows a better burn and injector duty cycles dropped:biggrin: I have my 03 regal up to 33.8 on a fairly aggressive stretch of highway that I test it on. I also ditched the mechanical fan for an electric unit. There is more tuning left in it because mpgs drop to 20-22 between 65-70mph. Still a little more tweaking to do in that area. The suburban shouldn't be considered a beater or commuter car given the prices for gas right now. I am beginning to think even the average 4 door 25-30mpg car isn't going to work when/if fuel goes beyond $7 a gallon.

 

[GNBRETT]

Nope, it's true. even going up slight grades at that speed. The 2WD is what keeps it from getting the mileage of the "other" suvs. I got an awesome deal on Jet DST and bumped the timing up four degrees at cruise speeds/loads as autotap wasn't reporting any knock. This allows a better burn and injector duty cycles dropped:biggrin: I have my 03 regal up to 33.8 on a fairly aggressive stretch of highway that I test it on. I also ditched the mechanical fan for an electric unit. There is more tuning left in it because mpgs drop to 20-22 between 65-70mph. Still a little more tweaking to do in that area. The suburban shouldn't be considered a beater or commuter car given the prices for gas right now. I am beginning to think even the average 4 door 25-30mpg car isn't going to work when/if fuel goes beyond $7 a gallon.

Gas won't go that high anytime soon. It will force other countries to start developing alternative fuels as a standard way of life and that would hurt Big oils profits. It will be back to $3 before it hits $7.

My 1990 Honda CRX HF model got 48 mpg. That was 18 years ago! It's a joke that these manufactors can't produce something similar for under $12k.

 

[klrv6]

Gas won't go that high anytime soon. It will force other countries to start developing alternative fuels as a standard way of life and that would hurt Big oils profits. It will be back to $3 before it hits $7.

My 1990 Honda CRX HF model got 48 mpg. That was 18 years ago! It's a joke that these manufactors can't produce something similar for under $12k.

I agree that it more than likely will not hit that mark. There is just the thought in the back of my mind about the implications of something like that happening. Very few people could afford to drive to work unless they car pool all day long.

 

[Pronto]

My 1990 Honda CRX HF model got 48 mpg. That was 18 years ago! It's a joke that these manufactors can't produce something similar for under $12k.

My wifes 84 Civic sedan used to get 45. Remember, today those little cars have much more weight in them do to the safety features-stronger body and airbags. Way better chance of surviving a crash in the new Civics...

 

[VKREGAL]

My dad has ford aspire which is a 1.3 hatchback car. It was getting between 39 and 43 mpg on average. Now it fell to 32mpg. My dad put premium in and it's back to normal. The regular is being mixed with ethonal as much as 20% so it's hurting the miliage. Probably more cost efficiant to buy premium to keep better miliage.

 

[Gary Wells]

Gas won't go that high anytime soon. It will force other countries to start developing alternative fuels as a standard way of life and that would hurt Big oils profits. It will be back to $3 before it hits $7.

My 1990 Honda CRX HF model got 48 mpg. That was 18 years ago! It's a joke that these manufactors can't produce something similar for under $12k.

We'll see about the "It will be back to $3 before it hits $7" statement. I would not bet on that. In finer detail, I think that it would depend upon whether you are talking reg or prem, and if prem, 91 or a state where it's 93, and whether the gas in that state is currently above average or below average. I personally think that in kali, premium 91 will hit $7 at some of the stations that are at the high end of the spectrum now. Basically, the brand name stations are just below $5 for 91 premium, and I am sure that some of the stations have already hit $5.

 

[GNBRETT]

We'll see about the "It will be back to $3 before it hits $7" statement. I would not bet on that. In finer detail, I think that it would depend upon whether you are talking reg or prem, and if prem, 91 or a state where it's 93, and whether the gas in that state is currently above average or below average. I personally think that in kali, premium 91 will hit $7 at some of the stations that are at the high end of the spectrum now. Basically, the brand name stations are just below $5 for 91 premium, and I am sure that some of the stations have already hit $5.

I would certainly bet on that. And that is regular gas. Yes there will be places that have higher rates usually due to state taxes but the average will certainly go back to the $3 range in time.

 

[Gary Wells]

I would certainly bet on that. And that is regular gas. Yes there will be places that have higher rates usually due to state taxes but the average will certainly go back to the $3 range in time.

For the sake of not arguing, Brett, I certainly hope that you are correct, but we shall see.