View Full Version : Fuels - Is There A Difference ?

23rd October 13, 01:08 PM
So what's the deal with Regular Unleaded, Premium Unleaded and Super Premium Unleaded fuels?
Is there any significant difference between them ? I mean enough to justify shelling out 10cents more per liter to get 'Super Premium' unleaded gasoline.
I have always been a regular unleaded kinda guy, but if I had a luxury car like NoB I might get the good stuff if I was positive it would make a difference of some sort.
That guy Tom I used to work with always filled up with Premium, even though he was driving an old beat-up Ford pickup truck. But he also owned a Jaguar, he just never drove it to work.
I don't know exactly how much he knew about cars, but he used to work for Ford at an auto plant. He was there for 25 years..
What do you guys think ? Is it just another gimmicky thing ? Another elite vs the middle class thing ? Or is Premium fuel really that much cleaner than regular fuel and better for your engine ?
NoB, you seem like a Super-Premium kinda guy. Are you ?

23rd October 13, 01:50 PM
I was going to mention oils too. Make sure you get it changed on schedule.

23rd October 13, 01:51 PM
NoB recommends using slick50 and Prolong.

23rd October 13, 02:29 PM
Ozz, the difference is Octane. The higher the grade, the more octane, which should lead to higher burning temperatures and less carbon.

The engine of a well tuned vehicle should have better performance with better fuel. My G37x can burn anything, so most of the time I use regular. However, I use premium on a highway trip. Makes acceleration faster, so passing on the highway is easier.

And yes, it's noticeable.

23rd October 13, 02:30 PM
I was going to mention oils too. Make sure you get it changed on schedule.

I know the importance of oil. Its the 'lifeblood of an an engine' according to Seinfeld's mechanic.
Premium fuel just doesn't seem like its worth it if you are only driving a domestic vehicle that retails for less than $30,000.

23rd October 13, 03:09 PM
Have someone else put gas in your car without telling you if it's premium or regular and see if you can tell.

24th October 13, 12:56 AM
I was going to type up something, but i gooogled it and reposted instead from: http://www.fuelly.com/tips/

Buy the proper octane for your vehicle
Contrary to popular belief more octane doesn't make your engine perform better nor is the gasoline any cleaner than lower octane ratings. Octane is a burn retardant, that means that it slows down the rate of combustion (burning) for gasoline. Octane ratings higher than those required by your engine actually decrease performance, albeit very slightly and probably imperceptibly at that, so buying higher octane ratings than needed just wastes money. As engines wear and tire out you may need a higher octane rating to control detonation, my last car wouldn't climb the mountains on 87 after about 100,000 miles and needed 89 - 91 to keep from pinging, but around town it did just fine on 87 octane up until I had it rebuilt at 195,000 miles.

I am not recommending violating your owner's manual requirements, if your owners manual says to use mid grade or high test then by all means do it, don't jeopardize your warranty to save a few cents per gallon, but if you're adding high test because you think it is better gas and your manual doesn't suggest or require it, then you should revisit this logic.