Does higher octane gas really help a car to get better milelage?

Question

I was wondering if it's true that higher octane gas gets better mileage. i did a little test myself several years ago, but the results ended up being about the same. Recently though, I added an octane booster to my tank when I filled up and noticed that I got an extra 10-15 miles more in the first quarter tank. Which would abmount to about 30-40 miles a tank. Is this just a coincidence?

Answer 1

Increasing octane raises the flashpoint and slows the burning process of gasoline ...if an engine does not have high enough compression to require higher octane there will be no improvement and it may in fact be harder to start and less effecient. Premium fuel is a waste in an engine that does not require it.

Answer 2

Most new cars these days that you buy will tell you in the owner's manual which octane the engine was designed for. If you use a higher or lower octane, then you won't get the best mileage out of your vehicle. Another thing that many people don't realize, is to check the air pressure in your tires, if they're under inflated, then it actually makes the engine work harder to move your vehicle, thus burning more fuel.

Answer 3

In a word, YES it is coincidence.
There is no more energy stored in the premium grade than in the regular unleaded.
The octane difference is related to the ability to suppress pre-ignition, or detonation, commonly called "ping", and that is the ONLY difference.
If your car calls for regular 87 octane, use it. If it calls for the mid-grade or premium, use it. That is the grade the manufacturer designed the engine to run on, and buying the higher grade is merely a profound waste of money.
This little "legend" comes from the old days when we would advance the ignition timing several degrees and then use premium or "ethyl" as it was known to reduce the ping. This gave us the effect of a bit more "seat-of-the-pants" driving, as well as the illusion of greater fuel economy.
The car's computer now controls the ignition timing, and if it detects a "ping" condition, it retards the timing until it stops.
Go here----->

http://auto.howstuffworks.com/question90.htm

…for a more complete discussion of octane.
As for the premium vs. regular fuel, they are identical in all respects except the octane rating. All have the exact same level of additives and chemical packages.

Happy Motoring

Answer 4

all gas is the same .. some cars are designed to run high octane fuel...follow the owners manual.. if it says use regular and u use premium ur just wasting money... if it calls for premium and u use reg u might see a slight drop in performance... but if the octane booster worked , then go for it ..

Answer 5

I would suggest you should check out your mpg.
Top your car up yourself to the absolute maximum reset your trip counter and drive around for a few days and note how many miles you do.
Refuel the car with higher octane and do the same. and again using additives

You may have to have your car re-tuned for the higher octane.

I don't think it will however as the higher octane will boost engine performance which I think would increase consumption. Isn't it more expensive as well?

Hope this helps
There a numerous ways to improve your consumption but altering your driving technique's
Take the lead of you foot.
Turn off the air conditioner.
Drive with the Windows closed
Don't drive around with a boot (trunk) load of junk

Answer 6

i own a repair shop,and the gas you buy isn't that much better ,what you done by adding the octane booster will help you more than than buying the real expensive gas,i seen a test done on some of the more expensive gas,and it didn't burn no better than the cheap unleaded regular did,and this was done by professionals,so you can add the booster to it,and help it more than buying the higher cost gas,good luck,i hope this help,s.

Answer 7

NO / work out the cost per mile factor.