Buying premium gas is waste of money

[manning]

http://money.cnn.com/2016/09/20/autos/aaa-premium-gasoline/

If owners manual calls for regular

Most car engines in America are designed to run on regular gasoline and, despite the superior-sounding name, premium gasoline provides no benefit over cheaper regular gasoline in those engines.


Premium has a higher octane rating than regular gas. That means it's able to tolerate higher pressures inside the engine. Engines designed to run on regular don't operate at pressures high enough to require the extra octane, so putting premium fuel into an engine that doesn't require it is simply a waste of money, AAA said.

"Drivers see the 'premium' name at the pump and may assume the fuel is better for their vehicle," said John Nielsen, AAA's managing director of Automotive Engineering and Repair. "AAA cautions drivers that premium gasoline is higher octane, not higher quality, and urges drivers to follow the owner's manual recommendations for their vehicle's fuel."

About 70% of vehicles now on the road require only regular fuel, AAA said. Still, about 16.5 million drivers unnecessarily filled up with premium at least once last year, according to AAA. That means Americans spent more $2.1 billion on more expensive fuel for no reason, the group calculated.

On average, premium costs about 50 cents a gallon more than regular, AAA said.


About 16% of Americans drive vehicles that actually do require premium fuel, though. These are mostly high-performance or luxury models. Using cheaper regular fuel in these engines can cause damage

In tests conducted along with the Automobile Club of Southern California's Automotive Research Center, AAA ran regular and premium fuels in various different car engines designed to run on regular. Using premium fuels in these engines did not produce more horsepower, better fuel economy or lower tailpipe emissions.

 

[Alesia]

Are there people who don't already know this? That's just shocking to me.

 

[grumpysteelman]

Totally accurate. Do not use premium unless your vehicle requires it. (All of mine do )

 

[tvguy]

Totally accurate. Do not use premium unless your vehicle requires it. (All of mine do )

Well, it is probably recommended, but under Federal law every car sold in the U.S. has to run safely on regular. An engine may not put out as much horsepower as the maker claims, but the computer senses and adjusts for the octane fuel you buy. There are exemptions, generally speaking those are limited production cars, no more than 500 a year sold in the U.S.
That's how a Toyota 3.5 liter puts out 268 horsepower in a Camry on regular fuel, and that same engine in a Lexus puts out 295 horsepower on premium.

Having said that, I do run premium in my 1965 Mustang.

 

[grumpysteelman]

Well, it is probably recommended, but under Federal law every car sold in the U.S. has to run safely on regular. An engine may not put out as much horsepower as the maker claims, but the computer senses and adjusts for the octane fuel you buy. There are exemptions, generally speaking those are limited production cars, no more than 500 a year sold in the U.S.
That's how a Toyota 3.5 liter puts out 268 horsepower in a Camry on regular fuel, and that same engine in a Lexus puts out 295 horsepower on premium.

Having said that, I do run premium in my 1965 Mustang.

Safely is a bit of a vague statement.

There isn't a magical octane sensor for low grade fuel (or "bad gas") when high octane is required. There is a knock sensor which will pull engine timing based on the resulting pre-ignition (aka detonation) events. This is when the fuel ignites before the spark plug fires. This is exceptionally bad for an engine for any extended period of time. In fact that Lexus that you certainly has more aggressive engine timing/tuning if all else is equal (if the engine itself is the "same" otherwise there would be no power difference with hi-test fuel).

Reduced ignition timings also result in reduced power and fuel economy and higher exhaust gas temperatures.

While a bad tank of gas or some low octane isn't going to ruin your car, running it as a matter of habit isn't good for it unless you know whether there are detonation/knock retard events.

Simply saying that it's "safe" as a blanket statement isn't totally correct. The car should be able to compensate, but the manner in which it does isn't graceful or proactive.

It's like turning the lights on after you've already stubbed your toe.

 

[ellie05]

I never meet someone that puts premium gas in a car that doesn't call for it, but I have meet people that put cheap gas in cars that call for premium. The later hasn't end up that well. We put premium in our Lexus and regular in the ford.

 

[Ranger111]

You "sorta" know not of what you speak.

If you get NON-ethanol primo gas, it can give a boost in horsepower and also run cooler, which is good for an engine. However, the average driver does not have access to "no corn squeezing stuff." Although it is around.

 

[tvguy]

Safely is a bit of a vague statement.

There isn't a magical octane sensor for low grade fuel (or "bad gas") when high octane is required. There is a knock sensor which will pull engine timing based on the resulting pre-ignition (aka detonation) events. This is when the fuel ignites before the spark plug fires. This is exceptionally bad for an engine for any extended period of time. In fact that Lexus that you certainly has more aggressive engine timing/tuning if all else is equal (if the engine itself is the "same" otherwise there would be no power difference with hi-test fuel).

Reduced ignition timings also result in reduced power and fuel economy and higher exhaust gas temperatures.

While a bad tank of gas or some low octane isn't going to ruin your car, running it as a matter of habit isn't good for it unless you know whether there are detonation/knock retard events.

Simply saying that it's "safe" as a blanket statement isn't totally correct. The car should be able to compensate, but the manner in which it does isn't graceful or proactive.

It's like turning the lights on after you've already stubbed your toe.

Safely may be a bit vague, but that is the law. Clean air act of 1970.

 

[Huff]

I've met a few that say they put premium in every few tanks to keep their engine in good shape. As the OP says, they just don't understand what premium is.

I use premium in my Nissan Juke. Its high compression, turbo'd. I use mid-grade in my hemi Durango as recommended by Dodge.

 

[Huff]

That's how a Toyota 3.5 liter puts out 268 horsepower in a Camry on regular fuel, and that same engine in a Lexus puts out 295 horsepower on premium.

Is the Lexus version modified in any way such as higher compression, different cam timing etc?

Or how a 2.4L in a Caliber SRT4 puts out 285HP. Of course, a turbo helps too!

 

[supersnoop]

Is the Lexus version modified in any way such as higher compression, different cam timing etc?

Or how a 2.4L in a Caliber SRT4 puts out 285HP. Of course, a turbo helps too!

Timing. If the engine management computer detects a "ping" from lower octane gas, it will retard the timing, decreasing power.

That said, I have two cars that "require" premium. I haven't seen any evidence of the regulation tvguy alludes to. There's no "recommended" in my manual.

 

[grumpysteelman]

You "sorta" know not of what you speak.

If you get NON-ethanol primo gas, it can give a boost in horsepower and also run cooler, which is good for an engine. However, the average driver does not have access to "no corn squeezing stuff." Although it is around.

Even ethanol free 87 or 89 octane is better than vegetable adulterated fuel of the same (or even higher) octane.

We have a local gas station with ethanol free 89 octane and some of the guys have (hopped up) cars with tunes for race fuel and 89 ethanol free. It's good stuff.

Of course e85 can make huge power at reduced efficiency - high ethanol actually has a cooling effect on the combustion process and can run lower (richer) a/f ratios to stave off detonation. It's like government subsidized methanol (alcohol rich race fuel) because it has LESS thermal energy.

 

[tvguy]

Timing. If the engine management computer detects a "ping" from lower octane gas, it will retard the timing, decreasing power.

That said, I have two cars that "require" premium. I haven't seen any evidence of the regulation tvguy alludes to. There's no "recommended" in my manual.

Clean air act of 1970 requires all cars (except limited production) be able to safely run on regular. Premium burns slower....which is why it doesn't ping, but slower burning fuel emits more smog. Those of us who were alive back then, and are car nuts remember it was predicted that this was the death sentence for performance cars. And if you have ever owned a 1972-1974 car you know about the poor performance. Or google information on some of the hot cars of the time, Camaro, Firebird, Corvette, Mustang, Charger, Challenger, etc, (1972-1974ish) and you will see lots of mentions of the engines being smog choked. 40 years later technology has arrived to overcome that.

 

[supersnoop]

Clean air act of 1970 requires all cars (except limited production) be able to safely run on regular. Premium burns slower....which is why it doesn't ping, but slower burning fuel emits more smog. Those of us who were alive back then, and are car nuts remember it was predicted that this was the death sentence for performance cars. And if you have ever owned a 1972-1974 car you know about the poor performance. Or google information on some of the hot cars of the time, Camaro, Firebird, Corvette, Mustang, Charger, Challenger, etc, (1972-1974ish) and you will see lots of mentions of the engines being smog choked. 40 years later technology has arrived to overcome that.

Can you cite a source that specifically shows the "regular gas" requirement? I'm well aware of the emissions requirements introduced and the associated drop in power output after the 1970 model year. Those changes were introduced in 1971.

 

[DisneyMandC]

I never meet someone that puts premium gas in a car that doesn't call for it, but I have meet people that put cheap gas in cars that call for premium. The later hasn't end up that well. We put premium in our Lexus and regular in the ford.

I put premium in my Lexus for a while too since that's what it called for. Bought it 55k miles (not sure if previous owner used premium) and probably put premium in it until about 90k miles when gas prices were over $4/gallon when I finally had enough. I used regular for the rest of the time and drove the car until 265k miles. It was still running when I sold it.

 

[ellie05]

I put premium in my Lexus for a while too since that's what it called for. Bought it 55k miles (not sure if previous owner used premium) and probably put premium in it until about 90k miles when gas prices were over $4/gallon when I finally had enough. I used regular for the rest of the time and drove the car until 265k miles. It was still running when I sold it.

I knew that when I bought the car we will have to put premium and while it hurt when the prices of gas where that high I just won't put cheaper gas. We just got a second Lexus I feel when you are spending that much money on a car I am going to go ahead and protect my investment. For reasons posted above why I will keep putting premium on the Lexus. We keep our cars a long time (not as long as you seem to keep them) and I want it running as smooth and as good for the engine as possible. Yeah I know it will run with regular gas, but there is a reason why they offer different grades.

 

[tvguy]

Can you cite a source that specifically shows the "regular gas" requirement? I'm well aware of the emissions requirements introduced and the associated drop in power output after the 1970 model year. Those changes were introduced in 1971.

Clean Air Act of 1970. Too many pages for me to find it quickly.

 

[supersnoop]

Clean Air Act of 1970. Too many pages for me to find it quickly.

I believe the Clean Air act mandated unleaded gasoline (as opposed to leaded), not "regular" octane.

 

[PlutoPony]

I believe the Clean Air act mandated unleaded gasoline (as opposed to leaded), not "regular" octane.

This.
The Clean Air Act of 1970 was about EMISSIONS i.e. basically taking lead out of gasoline. Octane levels are not addressed in the bill.
In 1990 the Act was mended and emissions requirements tightened, especially in areas that have higher pollution. One of the things it did was outlaw production of vehicles that burn leaded gas in 1993...maybe that's what tvguy was thinking of.

 

[tvguy]

This.
The Clean Air Act of 1970 was about EMISSIONS i.e. basically taking lead out of gasoline. Octane levels are not addressed in the bill.
In 1990 the Act was mended and emissions requirements tightened, especially in areas that have higher pollution. One of the things it did was outlaw production of vehicles that burn leaded gas in 1993...maybe that's what tvguy was thinking of.

No, octane is in there somewhere as well as unleaded. I may have to dig out my Car Magazines from then, because I've peeled so many lawyers on the Act, I still can't find it.
One thing I did not know, that is discovered in researching this, is apparently gasoline is not the same octane in every part of the country. Regular can be as low as 85 octane, and premium as low as 90. It's 87 and 92 here. Bottom line is, you're not going to hurt your car burning premium, but the trending story this week is your only burning up money you don't need to be spending..