Premium Gas???
 

Hi everyone!
I was wondering if anyone has done a cost/milage comparison with regular and premium gas. If you broke each km or mile down to a dollar figure, have you found any significant savings with higher octane?
Just curious, I've seen better milage with it, but I'm just wondering if it's worth the money? I'll be doing a little test and keeping track soon.

In my case with a turbo it is. The car is more responsive and FE is higher.

Being naturally aspirated, yours might not see a difference,

I put premium gas in my tercel a few weeks ago to see the effect on my fuel economy.

It might be from other reasons but I got 39 mpg instead of my usual 42. My tanks before and after were all at 42 mpg so i'm not buying premium anytime soon again.

In most cases the costs outweigh the benefits. As LeCouch pointed out, however, there are some cars that are designed with either higher compression, turbo chargers, or superchargers where performance drops and even engine damage can result from using lower grades of gasoline. You're generally better off sticking to what the owners manual tells you to use.

My tanks I've experimented with regular in my Acura were awful. My car would ping and run poorly at RPMs under 2500, so I was forced to drive in the mid-range of RPMs more, which led to poorer mileage. Then again, my engine is very high compression compared to most cars on the road.

if you run a scangaugeII you can see the difference in the ign function. as the previous posted said, you need to run what the car is designed to run on.

I had a post a while back about the dramatic effect NOT running premium had on the mileage and the performance on my trip to texas from CA.

If you are just an everyday driver, not paying attention to anything, it won't ever matter.
But if your on this forum and your trying to mazimize everything.....run what your car says to run.

ps running premium when the car says run regular is a waste (in my humble opinion).

I run premium in my Civic VX because it doesn't have Ethanol in it, 10% Ethanol and I see a 4-6 mpg drop, or about 10%, the premium here tends to be about 5% more expensive so it's worth it to me, my car also runs smoother.

The motorcycle shop that I used to work at would see a lot of motorcycles come in that were not running right because cheap gas was put in them, drain the gas and put in premium and they were fixed.

See what the car is set up for.
Using better fuel than that will generally not help much.

Using worse fuel will hurt the mileage though.



We've got premium diesel here as well, but for me, the reduction in fuel used doesn't compensate the higher price.
If I want to have a shot at record low fuel consumption, I'll use it ;)

In addition, not every car sees improvements in fuel economy when using the premium fuel.

In my case (no turbo) and old engine difference between lower and higher octane is about 0.5L/100km when we are talking about FE.
So yes the permium gas gives me a little bit better FE.
The best what you can do is check it by self with your car.

I found, in my car, that I would burn through regular faster than premium. Thats not backed up with any data but it was about three years ago on a stock tuned engine. I started running premium just because I figured it was about equal cost per mile.

I suspect the vehicle (and driver, and environment) of interest would need to be tested. There are probably way too many variables to make a useful blanket statement.

Before the Versa I had a Cabrio; its 2L was the only VW engine rated for regular gas. Back in 2007-2008 I ran a test on Shell Regular, Plus, and "V-Power." It was real-world, not tightly controlled, and not blinded, so it hardly qualified as an "experiment." But I ran the test for a LONG time to try to get reasonable data.

In my specific car (with me driving, etc.) I saw a slight FE improvement with premium, but not enough to offset the additional cost.

The data is available if you're curious, but it's on another forum and I don't know if I'm allowed to mention it here. Hardly worth looking at anyway; the improvement in my case was very subtle.

Rick