Why Cheap Gas Doesn't Pay In The Long Run

[99GTCoupe]

Mike, I think he meant in reference for a car not designed for it, but I dunno


I run 89 and my engine sound smoother than running at 87. There have been many posts on it and a decent amount seemed to say the same thing. I figured I'd try it out, and it works for my car. As for gas mileage, I dunno on that. All I know is I hit up BP, only change to that is the three times in the past year I had to hit the Marathon (Mobile? I think Marathon, though) by my house. Midgrade all the way

[peshields]

I put in the expensive stuff at the pump. I figured it out one day to see if i was losing money or not, and with the mileage change from 87 - 93 octane, I'm actually saving a little. My average city mpg on 87 was around 18.5, on 93 its 20. Now there is a $0.30 difference between 87-93 where I live, so if you figure that on a tank, (12 gallons) I'm getting 240 miles @ 93, and 222 @ 87, thats a difference of 18 miles. since 18 miles is nearly worth 1 gallon of octane 87, thats $3.75, (give or take depending on gas prices)

Now, compute $3.75 x 12 for octane 87 = $45
$4.05 x 12 for octane 93 = $48.6
Difference - $3.60

I can also break it down by price per mile,
87 octane - $0.2027 / mile
93 octane - $0.2025 / mile

Same mileage cost, but with 87 octane I have to fill up more often, and with 93 octane, my car FEELS like it runs better. Like eating steak vs ramen noodles, if they cost the same, why not eat steak?

[350rs]

dont forget that higher compression motors need that higher octane as well. my camaro was around 11:1 and ran terrible on 87. and best on 93 obviously. so thats all i ever ran in it. i tore that motor apart a month or so ago and its clean as a whistle. no fried pistons, nothing out of the ordinary for a 35k mile engine ( i wanted more power, thats why i tore it down). of course i had a warped head and fried seats when i hit about 330 degrees..

however. i run nothing but 87 in my GA and im gettin mid or upper 20's city and low 30's highway. Thats at around 70. i baby this car though, my toy is well. most of you know what my toy is..

[AaronGTR]

Originally Posted by peshields

I put in the expensive stuff at the pump. I figured it out one day to see if i was losing money or not, and with the mileage change from 87 - 93 octane, I'm actually saving a little. My average city mpg on 87 was around 18.5, on 93 its 20. Now there is a $0.30 difference between 87-93 where I live, so if you figure that on a tank, (12 gallons) I'm getting 240 miles @ 93, and 222 @ 87, thats a difference of 18 miles. since 18 miles is nearly worth 1 gallon of octane 87, thats $3.75, (give or take depending on gas prices)

Now, compute $3.75 x 12 for octane 87 = $45
$4.05 x 12 for octane 93 = $48.6
Difference - $3.60

I can also break it down by price per mile,
87 octane - $0.2027 / mile
93 octane - $0.2025 / mile

Same mileage cost, but with 87 octane I have to fill up more often, and with 93 octane, my car FEELS like it runs better. Like eating steak vs ramen noodles, if they cost the same, why not eat steak?

You have no idea what you are talking about. You can't just fill up at the station with twice with different kinds of gas and measure how much you put in and figure out your gas mileage by that. That is not a scientifically accurate method. There are too many variables like driving different routes, different amounts of throttle for traffic conditions, even weather... You'd have to run the car on a dyno at the same throttle position, for the same amount of time, with the same atmospheric conditions, and completely draining the tank when switching fuels to make sure they don't mix and change the octane. THEN, you could test to see if the octane changes your gas mileage.

Or you could just do some research and you'd find out it's already been tested and octane has absolutely NO affect on gas mileage... so you are wasting money.