'60 Minutes' of premium gasoline

In a December report on "60 Minutes," Andy Rooney said, "There are a lot of things I'd do if I was rich... I'd fill up with high-test gas instead of the 89-octane I usually buy now."

I don't know what kind of car he drives, but if it's one that doesn't require premium, he'd be wasting his money.

And "89 octane?" If he drives, say, a Lexus or BMW (which require premium - at least 91 octane), he's likely to void his engine's warranty if something goes wrong. And if he drives something that only requires regular, well, he's pouring money down the drain.

We've always said that if your car specifies regular fuel (87 octane), don't buy premium under the mistaken belief that your engine will run better. Most cars are designed to run just fine on regular gasoline. Furthermore, many cars that recommend premium fuel also run well on regular.

What should you do - even if you are "rich?" Check your car's owner's manual to find out if your engine is designed to handle either grade. Think twice about using the more expensive gas even if your owner's manual suggests "for optimum performance use premium." We have found that the differences aren't perceivable during normal driving. However, if your car "pings" or knocks with lower grade fuel, buy premium.

Again, for all models where premium fuel is not required, buying the high-grade gas is simply a waste of money... even if you have it to burn.

What octane do you use? Post your comments below.

—Mike Quincy

Read more about fuel economy.

Comments

[Cale Johnson]

04 Infiniti G35X- 87 Regular. 91 Premium recommended for best performance. I'm cheap.

[Pndxtr]

I use 89 because the car required 87 and the lower grade gas in our area is 85. The 85 I don't really understand because in all other parts of the country that I visit 87 is the low end.

[ronno3346]

I believe that your car will run on any fuel today because the computer will retard the spark if knock is detected. But if 91 is recommended, then you might get lower mileage from regular, so your miles per $ might be no better with regular. As stated above, go with what the manual recommends.

[Tom Wenndt]

In the Midwest, because of ethanol subsidies, 89-octane (ethanol-blend) fuel is often the cheapest fuel sold at most service stations. 87-octane "pure unleaded" is usually somewhere between a nickel and a dime more. Outside the Midwest, I just buy 87 - whatever is cheapest.

All my vehicles now run just fine on either 87 or 89. But for about 20 years, I always had a vehicle that, while calling for regular (and one for mid-grade), as they got to be older vehicles started needing and running better on premium fuel. That was expensive, but not as bad as it would be today.

[Brian]

I drive a 2006 Mazda 5 which requires regular gas...that's exactly what I give it.

[Roy Bridgman]

I use premium for my Subaru WRX because the manual says to and presumably the turbo demands it. But I don't like it! I also live in the mountains, and isn't knock more likely in harder mountain driving and lower pressure atmosphere?

[Kim Price]

I drive a VW Passat, which does require premium fuel (in fact it was one of the things Consumer's Reports dinged it on). However, in addition to the increased performance I get with premium fuel, I get significantly higher gas mileage. The higher coat of the premium fuel is more than offset by the increased gas mileage. This is something else to consider checking out if your car requires premium and you are thinking of skimping.

[David Evans]

I have continued to use 91 octane in our 2006 XC70. I had used the same in our 2002 Camry V6, since the owner's manual recommends it. However, at 125000 miles or so, I'm not too worried about it any more and have switched to regular. The gear changes seem a bit "off" now, but I haven't heard any pinging, and I can live with the lessened acceleration. But I would be curious about your opinion on the XC70. It's leased and may go back next year if we don't buy it....

[Wilfred Taguicana]

I'm using 87 for 2007 Honda Pilot and 2003 Toyota Corolla S. I do not see any difference with the higher grades.

[Ron Jacobs]

Though my Ford E250 van calls for regular I have found that premium increases my MPG by about 1.5 MPG or 11% while the price difference between regular and premium is only 10%. Also, when towing the engine runs much better with premium, e.g., transmission doesn't down-shift as often. I would love consumer reports to look at whether premium gives other vehicles a larger percentage increase in mpg than the percentage increase in price between regular and premium.

[Phil Waters]

The manual for our 2002 Volvo S60 specifies Premium fuel. However, the salesman at the Denver dealership said we could "get away" with using Mid-Grade due to the altitude. Out of habit we were using Mid-Grade on a trip to the west coast but did notice some coarse idling on occasion. Evidently, our vehicle noticed, too, as when we returned for a scheduled service the on-board computer tattled on us. "You vehicle has logged misfiring -- have you been using Regular fuel?" asked the service tech when we picked up the car. We'll remember that the next time we "go down the hill".

[Toby Radloff]

I recall that in times before cars had sophisticated fuel injection systems and computers, often times as an engine gets older, it would need more octane. Before the 1973-74 energy crisis, gas was 40 cents or less per gallon, with only pennies difference in price between regular and premium...and at the time Big Oil was heavily promoting premium gasolines. Although both vehicles and gasolines have changed, there are still those people that still love to give their vehicles "the good stuff", while others still believe that the older or more miles a car has, that it still needs more octane, computer or not. Premium was fine at the time when you were driving your father's Oldsmobile, but it's a waste of money today, unles your owner's manual specifically specifies premium.

[gladiola]

It's pretty funny how "Premium is recommended (but not required) morphs into "Premium is required" once you've graduated from the showroom floor into the waiting room sofas.

American companies are doing way better than their Euro and Asian counterparts in acknowledging customers' aversion to wasting money on premium. Here's a great link on the subject http://forums.caranddriver.com/auto/board/message?board.id=10&thread.id=4088

[Raymond Snyder]

My '02 Passat wagon with 4 motion and the 2.8 L. V6 recommends 91 octane and I have always run 87 octane and see no problems. My '03 Corolla takes 87 octane and gets 27-29 local and 35-38 on the road. Have touched 40 mpg twice, with much care.

[Russell Colin]

A) if the cars HP increases with premium fuel(stated in my Highlanders manual)won't the converse be true that for regular I'll need gas for the same distance i.e. 87/91? If this is the case then for 12,000kms/year the cost difference is <$40.00 CAD
B) EPA ratings - do they factor in if the manufacturer indicates premium only for the car?

[rich]

People that buy Premium Gas are wasting their money. It's equivalent to buying bottled water, instead of drinking tap, because you have faith, but no scientific data, that it's better for you. It's like buying more expensive name-brand prescription drugs versus equivalent generics.

Even smart people will argue the same old myths about Premium fuel but really the only one benefitting from your ignorance are the oil companies.

[VRob]

despite what consumer reports & others say, undoubtedly, higher octane fuel is better for automotive engines. It burns more thoroughly & efficiently- itself a definition of octane. That said, unless knocking is audible, the short-term impact of using low octane gas is completely negligible. But just like drinking tap water exposed to chemicals, over the long run it will be detrimental to your health, as is using low octane fuel in your car. If you're leasing or only going to keep it 4 or 5 years, have at it. If you hope to get 10 years out of your baby, don't put "rock gut" into it- in fact, stick with the mid to high grade Shell, Phillips 66 & other "top tier" fuels- they've been proven to be better than Exxon/Mobile/BP/Ammoco/Chevron/Texaco, etc

[celjak]

Premium gas is NOT better than regular, just different, and for most of you maybe worse! The misconception with octane ratings is as widespead as the flu, as I see everyday from people I meet and from reading these blogs.

If you don't know what premium gas is going to do if you put it in your car then you probably don't need it! Octane ratings are complicated, and just by reading the past few blogs very misunderstood, but to put it simply "the higher the octane the slower the burn" and vice versa.

If you have a car with a higher compression ratio (10:1 or more) you should be using premium (91 or higher), otherwise use the lowest grade you can find (87 or even 85), because it will burn cleaner, more evenly, and more efficiently in your car, which means better gas milage. You see, 93 octane will not burn completely in a "normally aspirated" (no turbo or supercharger) fuel injected engine, that doesn't have a 10:1 compression ratio or higher, which is about 98% of gasoline powered cars produced today. If you have a turbo or supercharged engine in your car, you will have to use premium (91 octane or higher). Turbos and superchargers force air into the engine increasing the compression ratio, therefore requiring a slower burning fuel.

Also, if you hear a pinging or knocking noise coming from the hood area in front of the car (where the engine is), drive the car until its almost empty, then use 89 octane for one (1) tank to see if the noise stops. If it does, you have carbon buildup inside the engine which is causing the compression ratio to increase, therefore requiring a slower burning fuel mixture, and yes it was probably caused by using a higher octane fuel or octane booster when you didn't need it, and NO, that is not covered under your warranty! Tell your "buddy" that told you 93 octane was "better" to pay for it!

Don't worry, unless you engine sounds like the Blue Man Group on New Year's Eve in Vegas, its probably not going to explode from this, but you may be doomed to be paying Premium prices, for "the GOOD stuff" from now on. A costly mistake many people make.

In closing, I would like to say that I don't know it all, but my credentials qualify me enough to write the aformentioned information on this subject. I have been professionally educated at two (2) Universities and one (1) Technical Institute in the USA, and have 19 1/2 years of developmental, and technical experience working in the automotive and motorcycle industries collectively.

I would also like to leave you with the notion "if you don't know what the effect or end result will be by doing something, you shouldn't do it!" Now if I could only get that message to the White House!

[bob]

The Car Talk guys say that it doesn't make any difference if you use premium or regular, even if the owner's manual recommends using premium, and I trust them as much as I trust CR!

That's what I use in my hand-me-down 2001 Lincoln LS V8. It's got more power than I need anyway.

http://www.cartalk.com/content/features/premium/questions.html#4

[JB]

Make "one" Octane for all gas powered engines, add octane boost, gas additives if needed. If you put 88 or 89 octane in the tank does your car know? no! does it void your warrantee? no! The car manufactures and the oil cartel, use the fact that you, not knowing, and the fear factor for you to trust them.
Batteries have been here for years and will be the future for Electric vehicles, The electricity to power the vehicles is the demand, it must not include OIL.

[Christine]

i have a regular Oldmobile, 2004 Alero, no turbo or fancy crap. but i do get about 3 to 5 mpg better on premium. or it could just be that i have to go to a better gas station to get premium. Hucks dont even sell premium gas anymore after gas hit $3 a gallon. now i go to marathon. which i think is better anyways.

[Zahid]

I have 97 Jag, XJ6L, requires premium, but since I bought this as used in 2003, I never used premium, always used the cheapest one ..never had any issue runs great..

[Sam]

Octane rating only rates the fuel's resistance to knock or detonation. It does not have anything to do with the rate at which the fuel burns. If your car has a high compression engine or forced induction (turbo or supercharger) it will most likely require higher octane to run properly.

Increasing engine compression produces more power and better fuel efficiency. Therefore, car manufacturers looking to maximize engine efficiency often look at increasing compression as the means to that end.

However, compression is limited by detonation. At some high enough compression, any fuel will detonate. Detonation is explosive combustion of some of the fuel in the chamber complete with shockwave and potential damage. It's like having little hand grenades going off in you engine 3000 times a minute. Leads to bad things (blown head gasket, cracked piston rings, destroyed pistons, broken connecting rods, mucho $$$)

Due to advanced computer controlled fuel injection, operating a high compression engine on lower than recommended octane fuel will usually work okay. However, it will reduce engine power output and increase fuel economy and emissions. It will also increase the possibility of detonation damage. While computer controlled fuel injected engines do have the capacity to adapt to lower octane fuel, there are limits to how much they can correct. Additionally, they generally correct for knock by adjusting the ignition timing, reducing the time between ignition and opening of the exhaust valve, which reduces the peak cylinder pressure(a key component in detonation). This can prevent knock, but it also reduces power and increases the amount of unburned fuel blown out the exhaust, which is bad for fuel economy and emissions/air quality.

So keep that in mind when you decide to put lower than recommended octane fuel in your car. Reduced engine efficiency means poorer fuel economy and a dirtier exhaust. Plus the car will be less responsive and more likely to be damaged by knock.

If you want a car that runs on regular, buy a car that's designed to run on regular.

[lexusgs300]

2006 Lexus GS 300. Wants 91, has a direct injection engine with an 11:1 compression ratio. I give it 91. Wish i had the GS 350, makes 300 hp. the 300 only make 245. Kind of a dog.

[likeyouneed2 kno]

I drive a 1992 Geo Storm (NOT a metro!) and since i have started using 92 octane gasoline i have noticed better fuel economy and also a sharper throttle response even though the manual says regular unleaded. beats me, but I'd say premium is better.