Premuim gas in vehicles ???

[Alex F]

This is wrong, wrong, wrong. Using higher octane rating WILL NOT do *ANYTHING* to improve mileage or efficiency of burn unless the engine REQUIRES it. Although results may mislead you if you're dealing wiht an engine that's out of tune or inefficient to begin with.

You're completely wasting your money if you think putting premium will somehow "be better" for an engine that doesn't require it. Now, there may be some factors like additives (detergents and such) that may be found in given brand's premium blend that's not in the loca cheap place's regular. But even that's unlikely given today's fuel formulations.

It's just as true that changing your oil more frequently will do more to prolong the life of the engine than spending excessively on fancier oils. It had more to do with the changing of the filter than anything else.

If it makes you feel better to believe the myths, then fine, but don't go spreading that nonsense to others. It just isn't true.

wkearney99,

First of all, I just expressed my opinion, just like you're. Second, you say that I'm wrong, but provided very general statement with no specific facts.
I don't have any labwork scientific writeups or facts as well, but I go by basic facts, which are:
1. Manual for my SUVs state that premium is recommended for better performance and fuel economy.
2. I had simply tested the theory on several occasions and all can say that I loose about 70-100 miles per tank when filling with 87 vs 91 (mix driving city/hwy). This simply means the vehicle lost performance as well as the fuel economy. Without analyzing any science behind it this is a simple fact I've observed first hand. So far this backs up what the manufactory recommends.
3. Going back about 10 years, I drove cars that performed exactly the same. Going back 20 years, some cars wouldn't even drive on 87.

Again, I just shared my experiance and opinion. If you have different experiance and specific facts I'd love to learn them and see what tons of people, including myself, are missing. But in the end, despite all the facts and arguments, I would still have only one question "why does a car/suv looses in the mileage when filled with lower octane gas?".

Thx,
Alex.

 

[wkearney99]

As I suggested, if a vehicle doesn't require the higher octane it's a waste. Your's did so it's no surprise that following the manufacturer's directions worked. There's no "opinion" there, that's just following instructions. It's a mistake, however, to extrapolate what works with an engine that would REQUIRE it to one that won't.

Search the web on what octane ratings mean and how they affect the operation of an engine. Likewise, as I suggested, older engines had different requirements, and fuel formulations varied. Neither of which is true in engines or formulations today that are designed to work quite well on regular octane fuel.

The fundamental difference is how the fuel burns. Various factors like RPMs, higher compression ratios, combustion chamber configuration, spark duration and the like all come into play. Most of which is manifest as knocking or pinging in an engine not designed for using a lower octane fuel. In an engine designed NOT to use premium you actually present the risk of getting worse performance and actually cause higher exhaust emissions. All summarized as a waste of money to use a higher octane than necessary. But hey, feel free to waste your money convincing yourself of something that just isn't true.

Enlighten yourself, don't spread myths.
(And adding O's isn't how to spell lose, but that's just a pet peeve....)