Any good reason to/not to use premium over regular gas?

[ShaggyTDawg]

So I just got my new 2011 TE and did my first road trip. I knew what kind of mileage to expect and have no issue with it. But I come from driving an Acura that required premium. My friends always used to cringe at me when I mentioned I had to put premium in b/c "it costs so much more". At that point, I'd usually be the stubborn @$$ and point out to them that it actually doesn't... For my Acura, I'd need about 14 gallons when the empty light was on, and my local gas station charges $.15 more per gallon for premium over regular. So that comes out to a whopping $2.10 extra for my fill up... say an average of $3.50 a gallon over the last year or so (just a rough number) that puts it at a $49 tank of gas... what's an extra $2.10 on top of that... and mind you... as the price of gas goes up... that extra $2.10 per tank stays the same...


So now I've got my 4Runner TE, and I'm told by the dealer do regular. So now I ask the more informed, opinionated, and probably knowledgeable masses: Is there a reason not to use premium that's performance or maintenance related? Or the vice versa?

I know my Acura needed it b/c some engines have a higher compression ratio or something so they need a higher octane fuel. But I've always heard higher octanes perform better, give more power, maybe better millage, better for the engine, etc... so wanted to know if any of that is really true... and should any of that be considered here.

For an extra $3 on a 20 gallon fill up, I can continue to deal w/ premium if there's some benefit to it.

Thanks ahead of time!

 

[StRanger7032]

There is no benefit to using premium on an engine that's designed for regular. The ECU is calibrated for regular. Using premium on a car that's designed for regular is a waste of money. The gas companies use terms like "premium", "super", and "ultimate" to entice customers to buy more expensive gas, thinking its better for their vehicle. You wouldn't want to use regular in a car that requires premium, due to high compression or turbo charging. The only exception I know of is a vehicle with very high mileage with detonation issues, which might benefit from higher octane. Don't waste your money-the 4Runner is designed and tuned for regular!

 

[Jensent]

x2!!

 

[kingpin748]

The best reason would be it's a complete waste of money. You're not going to see any performance increased using premium.

 

[STLDAVE]

Look at it like this, a gallon of regular contains the same amount of energy as a gallon of premium, so the mileage, performance, etc. is the same. Premium's advantage is the higher resistance to detonation (engine knock) that is required by high compression engines, turbo charged engines, etc. Since the 4 Runner doesn't require the extra "knock" protection, why would you want to use premium?

 

[ShaggyTDawg]

Look at it like this, a gallon of regular contains the same amount of energy as a gallon of premium, so the mileage, performance, etc. is the same. Premium's advantage is the higher resistance to detonation (engine knock) that is required by high compression engines, turbo charged engines, etc. Since the 4 Runner doesn't require the extra "knock" protection, why would you want to use premium?

This is the kinds of explanations/reasons I'm looking for! Keep'm coming if there's anything else not yet said.

 

[tlflow]

once in a while

Running a tank of higher octane fuel every so often, will insure that you fuel system remains clean. Fuel from name-brand retailers will be consistent and higher quality than no-name fuel, less risky choice.

Most premiums (91/93) have too much ethanol in them, which is crappy transportation fuel for a number of reasons. Alcohols are very good fuels for drag racing.

The oxigenate MTBE was far better fuel, but the government mandated it's replacement with ethanol. This drove the price of fuel up and our milage down.

Quiz: Is it really more environmentally sound to burn 15-20% more fuel because it has 10-15% ethanol?

 

[Jtraskell]

It was explained to me a long time ago like this. Think of regular gas as a single sheet of regular printer paper. Premium gas as a piece of cardboard about half the size of the sheet of paper. Ignite both of them with a lighter. Both will actually put out the same amount of heat, but the paper will ignite faster, cardboard slower.

All the things STLDave and others said above is true, but I would add, premium gas was actually developed to help stop "pre-ignition" and "post-ignition" from vehicles back in the 60's and 70's.

Back then, leaded gas and the type of engines being built, including lessor ignition systems. allowed carbon build up on piston heads. This carbon would super heat during operation. Regular gas being highly explosive, (lower octane) would ignite to soon when entering the cylinder causing "pre-ignition". (It's the pinging sound you can still hear today in the higher compression engines referred to above)

Then, when the operator would turn off the car, unburnt gas fumes would continue to ignite even with the engine off, causing "post-ignition". The vehicle would act as though it still wanted to start way after the vehicle was turned off. (You don't hear about this anymore unless you have a pretty old car).

Premium gas being "less explosive", (higher octane), helped prevent these issues. And, it still works better in the modern higher compression engines.

 

[Jtraskell]

Running a tank of higher octane fuel every so often, will insure that you fuel system remains clean. Fuel from name-brand retailers will be consistent and higher quality than no-name fuel, less risky choice.

Most premiums (91/93) have too much ethanol in them, which is crappy transportation fuel for a number of reasons. Alcohols are very good fuels for drag racing.

The oxigenate MTBE was far better fuel, but the government mandated it's replacement with ethanol. This drove the price of fuel up and our mileage down.

Quiz: Is it really more environmentally sound to burn 15-20% more fuel because it has 10-15% ethanol?

Agree with the better quality of the name brand fuels for detergents and other additives etc., but higher octane? I'm thinking the detergents/additives in name brand regular grade will accomplish the same benefits rather then running a higher octane in an engine not designed for higher octane. Based on what I have been told, there is the same amount of that yucky stuff called ethanol in every grade, up to 10%. Just a thought.

 

[1000MPH]

IMO, the only reason is if you know the higher grade is Ethanol free and the other grades are not.

 

[user name:]

the higher the octane, the slower the burn/ignition... higher octane is good for cars designed to run higher octane fuel... the 4runner is not one of those vehicles.

 

[Quentin]

IMO, the only reason is if you know the higher grade is Ethanol free and the other grades are not.

Ethanol has a higher octane than premium, so wouldn't it stand to reason that ethanol would boost the overall octane of the mix and be more likely to find itself in a premium blend?

 

[MattH72]

A station in my town has ethanol free premium gas. My wife's new maxima is supposed to run premium, so thats what we use. I filled up the 4Runner last night with the same ethanol free premium. Any reason that is a bad thing even though 4Runner doesn't need premium?

 

[Jtraskell]

A station in my town has ethanol free premium gas. My wife's new maxima is supposed to run premium, so thats what we use. I filled up the 4Runner last night with the same ethanol free premium. Any reason that is a bad thing even though 4Runner doesn't need premium?

Will it destroy you motor? I think not. At least not right away. But, if the motor, ECU and everything that goes with it is designed to burn regular gas, which has a lower octane, (but it burns faster), over time I can't see it helping your motor.

Using higher octane will not allow your vehicle to run at it's best efficiency, it will cost you more, and in the long run you will probably run into more mechanical problems then if you would have followed the manufacturers recommendations.

 

[iDRiVaT4R]

I ran premium in my 2010 once and didn't do a thing for mileage or power.

I always get better mileage and a slight performance benefit when I fill up with Chevron though vs. Vons, United Oil and similar stations. The Techron apparently helps a lot in keeping the injectors clean and what not. I read that the Techron Fuel System Cleaner is the best you can buy so I placed an order for a 6 pack online at Autobarn last week. Came to $9.95 per 20oz bottle vs $12.99 at local Auto parts stores.

 

[1000MPH]

snip... it will cost you more, and in the long run you will probably run into more mechanical problems then if you would have followed the manufacturers recommendations.

That's a huge stretch. Where have you heard this?

 

[JB.]

It's a fuzzy subject but it's apparently not as simple as just compression ratio. 2005 owners manual states the following:

"Select Octane Rating 87 or higher. For improved vehicle performance, the use of premium unleaded gasoline with an Octane Rating of 91 or higher is recommended."

Both the '05 engines have compression ratios lower than the dual-vvti V6 (10:1 to 10.4:1)

 

[thebwlife]

Just use regular.

Why try to re-engineer what toyota has already spent billions of dollars and decades of R&D perfecting. Their engine program has a pretty good reputation.

 

[Jtraskell]

That's a huge stretch. Where have you heard this?

1000MPH, I can understand your concerns. These were the first two articles that came up in a simple Google search. Bottom line, I do not think it is a real stretch to suggest long term damage may occur if running the wrong fuel over a long period of time.

Here is a pretty good USA today article from 2003.

USATODAY.com - Why use premium gas when regular will do?

Although the article is mostly concerned with those folks burning Regular in engines designed for premium, there are a couple of noteworthy paragraphs towards the end:

Premium, in fact, sometimes is worse fuel than regular. It resists knock because it's harder to ignite than lower-octane fuels. As a result, some engines won't start as quickly or run as smoothly on premium, notes Gibbs, the SAE fuel expert.
High-test does have a potential fuel economy benefit. It is slightly denser than lower-octane gas, meaning there's a little more energy in a gallon. But the small difference is hard to measure in real-world use, and that same density can contribute to undesirable buildup of waste products inside the engine.No data show that engines designed strictly for regular run better or longer on premium.
The Federal Trade Commission, in a consumer notice, emphasizes: "(I)n most cases, using a higher-octane gasoline than your owner's manual recommends offers absolutely no benefit. It won't make your car perform better, go faster, get better mileage or run cleaner."
There is "no way of taking advantage of premium in a regular-grade car," says Furey.
"There is no gain. You're wasting money," insists Jim Blenkarn, in charge of powertrains at Nissan in the USA.

This is an article from consumer reports which describes why some vehicle engines CAN run on Regular even if designed to run premium. The last paragraph of the article is the concern. If our Toyota 4 runners “knock-sensors” can advance the timing as described below, well then maybe all is good. But if not, driving over a long period of time when the engine is out of time, I think you will agree, is not a good thing.

Premium gas: A waste of money?: Gasoline pricing, high octane

Some engines for which premium gasoline is recommended can run on regular without problems. That's because the engine's knock-sensor system detects the presence of uncontrolled burning in the chambers. When it does, the engine's computer-control system re****s engine timing, eliminating the knock but slightly reducing power. If you don't mind giving up some performance, you can run these engines on less-expensive regular gasoline. To check whether your engine is capable of running on regular gas, read your owner's manual or ask your dealership's service department.

Be safe....

 

[1000MPH]

Good reading but I still don't see how you could draw that conclusion.