Better Gas Mileage with premium fuel

[Chubz]

Who else follows that "rule". People tell me that it isnt true, but it definitly is noticeable on my 08 Accord V6. I usually fill up on monday before work and don't refill until wednesday night after work. With regular gas im filling up on Wednesdays before work. For the extra $2-3 dollars a fill, it's worth it.

[RNPoo7]

I use premium all the time. I got in that habit after turbo'ing the integra!

[Crono139]

I only put regular in my Accord.

Never tried premium gas.

[dohcdelsol93]

For the most part it doesn't really make a difference unless you have a higher mileage engine or higher compression engine. The exception is newer highly advanced EFI systems like you find in cars like Hondas, Toyotas and so on.

The oct rating changes the lowest possible temp that the fuel will ignite. The lower the oct rating the lower the temp it will ignite.

So unless you have alot of cyl pressure caused by boost, high comp or blow by from wearing rings/cyl/ring lands it's not going to help you out any.

My 9:2 comp bike will get 70 mpg around town on 93 oct BP or some cheap 87 that I take out of a customers lawnmower.

So if you have an older EFI car or a carbed car the answer is no, it won't help.

If you have a performance car or a newer car the answer is yes.

[Agent Zero]

Originally Posted by dohcdelsol93

For the most part it doesn't really make a difference unless you have a higher mileage engine or higher compression engine. The exception is newer highly advanced EFI systems like you find in cars like Hondas, Toyotas and so on.

The oct rating changes the lowest possible temp that the fuel will ignite. The lower the oct rating the lower the temp it will ignite.

So unless you have alot of cyl pressure caused by boost, high comp or blow by from wearing rings/cyl/ring lands it's not going to help you out any.

My 9:2 comp bike will get 70 mpg around town on 93 oct BP or some cheap 87 that I take out of a customers lawnmower.

So if you have an older EFI car or a carbed car the answer is no, it won't help.

If you have a performance car or a newer car the answer is yes.

I love it when someone knows what the hell they are talking about.
Great post mang!!!! Repped

[oceanspraypink]

Originally Posted by dohcdelsol93

For the most part it doesn't really make a difference unless you have a higher mileage engine or higher compression engine. The exception is newer highly advanced EFI systems like you find in cars like Hondas, Toyotas and so on.

The oct rating changes the lowest possible temp that the fuel will ignite. The lower the oct rating the lower the temp it will ignite.

So unless you have alot of cyl pressure caused by boost, high comp or blow by from wearing rings/cyl/ring lands it's not going to help you out any.

My 9:2 comp bike will get 70 mpg around town on 93 oct BP or some cheap 87 that I take out of a customers lawnmower.

So if you have an older EFI car or a carbed car the answer is no, it won't help.

If you have a performance car or a newer car the answer is yes.

So how new we talking? And dang boy have a new baby at home and still have time to write all that, my hats ff to you, lol!

[dohcdelsol93]

just about any advanced distributorless EFI system. It's different for all manufacturers and models. Some companys are better with it than others. IMO american vehicles have still not made an EFI system that impressed me. IMO the 92 honda EFI system was far superior and efficient than todays GM or Ford EFI systems.

On newer cars the ECU relays alot more info back and forth to the sensors than what it used to so the fuel/timing maps are always changing depending your driving habits and or conditions. On some newer cars you even have individual coils on every spark plug which even further advances the capability to play with ignition timing. This way a factory car can actually achieve MBT at any normal diving conditon or at least come as close as humanly possible.

This is the reason it can be much harder for tuner (rice boys) to do modifications to their cars like boost/nos because the engine management system is much more complicated. The ECU is actualy more like a computer now. When a new vehicle comes out (like the RSX or S2K did) it takes a few years for the tuner scene to catch up.

MBT (mean best timing) is where your ignition timing is at the optimal point of both efficiency and power. This point changes at different altitudes, temps, gas quality, RPM, humidity, air pressure and load.



On alot of the E85 vehicles you even have a sensor in the fuel tank to test the density of the ethanol (alcohol gas) so it can run at optimum perfomance since one tank of fuel can vary so much from another.

[oceanspraypink]

Okay Josh you have to use small words dear...Sorry Im watching Shrek 2, lol!

So should I start using premium in the exterra to help with my SUCK gas mileage or don't bother I won't see enough of a difference? It's only a 2001, right now, well when gas was around 2.60 a gallon I was getting about 115 miles on $20!

I've heard that the E85 is cheaper, but it doesn't go as far as regular gas...I don't know I don't have a flexible fuel vehichle.

[dohcdelsol93]

I'd avoid all E85 unless your car is made for E85.

Like i said, it's not a consitant fuel.

I'm not sure if it will help your gas mileage or not if you run high oct. The best way to try is by hwy driving. Go two tanks on the hwy with regular then two tanks on prem. Then see how far the 2nd tank goes on each gas type.

It's going to be hard to tell if it helps or not by just driving around town on 20 bucks of gas.

Stop and go traffic can really throw off your mpg calculations. Unless you have an off road place to test your driving conditions are going to change pretty much every time.

[Agent Zero]

Damn Josh.. You got that crazy knowledge.... Repped again.

[WonderMike]

Josh is like the internal combustion genius.........repped for your vast knowledge

[dohcdelsol93]

dude, typos own me. I need to start proof reading. I need sleep....