Car Talk and premium gas

I heard it and was puzzled, but then I don't know the new electronics and the like. Would like to hear what people have to say.

Maybe asking on their web site would bring clarification.

Read your owner's manual for what you should use in your vehicle.

Cars that require or "recommend" premium often run more efficiently or more powerfully on premium. Cars that recommend regular (most cars) usually get zero benefit from higher octane, so premium is simply a waste of money. Here in the most highly marketed-to-in-the-world North American society, we tend to buy into the "upscale" mentality of more expensive = better.

I have MPG data from every tank of gas for my 2005 Tacoma in Quicken. Toyota recommends premium for the 4L V6. If I spend the ~$0.30/gal extra for premium, I get enough extra miles to actually make it slightly cheaper per mile than regular, and get better performance under stress (towing and hot / higher atmosphere) as a freebie!

My '99 Wrangler and 2001 H4 Subaru got exactly the same mileage and no noticeable performance gain on 87 vs. 91+, so premium was a complete waste of money.

Cars that _require_ higher octane in the manual can be damaged by lower octanes, and should not be run on regular.

Premium is a waste of money. Yes performance may suffer but not for a daily driver. No damage will result. What if premium isnt available. Do you really think your car will explode if you use regular? I have personal experience with a 2001.5 Passat that "required" premium fuel. Never used it and car ;lasted 140k + before tradein. None of the numerous mechanical problems car suffered could be attributed to gas . You are free to give oil companies more but I wont

Thank you for this excellent post. You said it far better than I could, especially with your empirical evidence to back it. I don't know why people buy cars that require premium gas and then don't feed the cars properly. Why did they buy those cars, then?

Hi,

Barry already said everything that was going thru my head. My old Subie says "regular" and only during the very hottest months of summer have I been able to see any difference when I've tried "higher" grades (cuz it pinged like crazy.)

OTOH, a slightly newer 3.0l V-6 Camry sitting on the driveway will run on anything, but DOES do better, as the book says it will, by going to a higher grade just as Barry's Taco does. I assume it's got a lot to do with improving fuel and engine management systems as the years go by?

Rick

A sample of one, in sea level NJ.

-rick- wrote in news:h_adndyDTIpAIoDbnZ2dnUVZ snipped-for-privacy@comcast.com:

It's generally considered a waste IF the manufacturer recommends regular fuel. If the owner's manual states premium fuel you should be using it. Here is an article on this topic:

I can tell you that an STi can produce audible pinging on 91 on a hot day from experience; because the base timing is reached and it can't be retarded further. Just about every automotive source indicates that audible pinging in a modern engine with a knock sensor usually means damage is occurring. Given that, I only use 93 or better in the STi, and drive sedately on 91 in the summer. So, you can bet regular would definitely damage the engine if driven hard.

Pinging is fuel detonating, not burning smoothly and not normal. That is bad. If pinging is present in an engine, excessive amounts of heat and stress are generated and will cause destruction of engine components such as pistons and valves. I'd check that out if I were you....try Google....don't take my word for it. As a rule (in the UK) the higher octane fuels we have (95 to 102) also have detergents and other additives to keep the fuel system clean which is an additional benefit. My WRX most certainly runs better on 99 (+5% bioethanol) than 95 so better all round, a little greener and who cares about a few pennies extra per litre for a top quality product?

-C-

Hi,

Methinks you've got it a bit off: maximum efficiency comes JUST BEFORE pinging according to all sources I've ever researched. Pinging is uncontrolled, therefore it's hard to believe it's efficient!

Rick C

snipped-for-privacy@backpacker.com wrote in news: snipped-for-privacy@y80g2000hsf.googlegroups.com:

Not unlessyou are using a Bourke engine

Pinging aka detonation is not good for conventional internal combustion engines:

It is caused by an instantaneous ignition of the remaining fuel/air mixture in the form of an explosion. The cylinder pressure rises dramatically beyond its design limits and if allowed to persist detonation will damage or destroy engine parts.

Source

Pinging is NOT normal and it is not good for the engine. If you think otherwise, go read some more.

What the fk ???

And is in a danger zone once pinging starts. Pinging is NOT normal and extremely distructive.

It may well be, but that's not what you said.