Was wondering how many people believed that high octane is a waste of money

[nymets11]

There were some articles recently written about how high octane doesn't really do that much better than regular gasoline. So I was wondering how many people believed that high octane is a waste of money and it's all the same. I

[theholycow]

In cars that specify regular: It is definitely a waste. There is nothing to gain.

In old cars that specify high octane: Required.

In modern cars that specify high octane: Better performance, possibly better fuel economy, but harmless to run regular.

[FrugalFloyd]

My 2002 Nissan recommended, but did not require, premium. My Scion recommends regular. They both got steady diets of regular, with no ill effects.

High octane fuel's only use is to increase knock resistance. No knock problems = no need to, and no advantage from, using premium.

[bobc455]

Originally Posted by theholycow

In modern cars that specify high octane: Better performance, possibly better fuel economy, but harmless to run regular.

Disagree. The knock sensor is a reactive device. It retards after it hears knock, then advances timing again until it hears knock again. It will prevent an immediate catastrophic failure, but over 100k miles you'll have an accumulative effect and you'll lose a head gasket or crack a head.

-BC

[imzjustplayin]

Originally Posted by theholycow

In cars that specify regular: It is definitely a waste. There is nothing to gain.

In old cars that specify high octane: Required.

In modern cars that specify high octane: Better performance, possibly better fuel economy, but harmless to run regular.

Not always true.. There are definitely exceptions to the rule on both sides.. On my sister's Volvo s60, it specifies premium and I think for the most part, that's an accurate assessment since it's a turbo'ed car. It's true you can safely use Regular gasoline when it's very cold outside but get above 70f and you'll likely need to use Premium. Some cars are super high end and while the knock sensor is suppose to help, the car can only do so many things to avoid the knocking and depending on the design, sometimes it really does need premium regardless. My friend's chevy truck specifies regular but because it knocks badly every time it ascends a steep hill, he uses premium. I usually recommend regular gasoline to most people and then make exceptions for premium gasoline when necessary. One interesting example of using regular being better than premium, on my dad's ES350, it specifies premium but because it has the same engine as the camry which uses regular, it's better for him to use regular. You can even see the decrease in fuel economy by using premium when you compare the ES350 with the V6 Camry as the V6 Camry is rated at 23 and the ES350 at 22.

I'd say use regular unless there are some extenuating circumstances that call for higher grade fuel. Some cars are so poorly maintained that using premium fuel is a necessity and some other cars are turbo'ed and really do need premium fuel.