Premium gas, or?

[NotlocTRD]

Hi folks,

Does the FR-S/BRZ HAVE to run on premium gas, or could it run on regular/mid and still function efficiently? Would it hurt the engine to run mid grade or regular? Would Scion advertise Premium as getting the most performance or would it run the risk of damaging something if anything else is used?

Thanks!

[fistpoint]

Says use premium.

In all those cases I do believe it is safe to use the lesser gas, but it results in less power and possibly less efficiency which both offset the savings. So you'd wind up spending the same amount overall, but with less power.

[Lonewolf]

Premium gas is required. In an emergency you can fill it up with less, and the car will pull timing, but the car will run like crap.

Premium gas is only 20 cents more per gallon than regular. Is it really worth potentially harming your engine in car that you just paid nearly 30G's for to save twenty cents a gallon?

Plus this car has very high compression, you are risking knock and pinging by running less than premium, and that is bad, mmkay?

[Mari0]

Many threads on this one

It still never seizes to amaze me how people are ready to pay $25k+ for a car and are willing to be cheap on gas.

Not an expert on engines and fuels but I am guessing if it's optimized to run on premium, anything else would give you shitty results and might hurt your engine.

They win nothing by advertising it as premium as they don't get $ from you whether you use premium or regular. If anything, they might lose some potential customers by saying you need premium. Point is, if they are saying you need it, you do. It will run on regular but do you want to put your car through that?

This was a long way of saying, if you are gonna buy a brand new car for over $25k, don't be a cheap a** when it comes to filling it up.

[Smitty_89]

I may be wrong but I think cars nowadays have technology to detect the use of lesser gas and the engine performs accordingly, so yes you get lesser performance but I do not believe you can damage or hurt you engine if you went with lesser gas for a few weeks or something. I would of course never do that and would always buy what the manufacturers suggests but its not the end of the world if you accidentally fill up on lesser gas once or twice.

Edit: I was wrong, so ignore everything I said. lol

[Alias]

If you can't afford the 20 cents extra you shouldn't even dream of buying this car.

You're talking about 2 bucks or so whenever you fill up, does that REALLY matter?

Originally Posted by Smitty_89

Please correct me if Im wrong

You're wrong, it actually can damage your engine.

[Genomaxter]

You can indeed damage your engine if you run regular. Due to the high compression, it needs the 91 (minimum) octane to operate normally. If you put regular and then go into a heavy load situation, your engine will start to knock. It will pull timing but at the same time is also trying to meet the required torque demand (pedal position) and will start a nasty cycle of retard and advancing. Knock destroys engines if it happens far too often over a period of time or too much at once. You want to be cheap? Start by not paying 25k + on a car like this.

In short, dont buy this car if you want to run regular. Your wasting money.

[Xdragonxb0i]

if you calculate the cost of premium, it is an aprox an extra $5 dollars, that is a value meal

[NotlocTRD]

Just to clear things up, I have no objection to buying premium gas for the FR-S. A buddy asked me if I knew anything about it and if it was designed to utilize the lesser but perform the best with the high test, but I had no idea so I thought you guys might know more about it.

[YukiHachiRoku]

don't cheap out!

[Pekingduck]

I think out would be okay at lower rpm, but at higher rpm you might cause detonation. With the frs why would you stay at low rpm?

[DeeezNuuuts83]

Originally Posted by Smitty_89

I may be wrong but I think cars nowadays have technology to detect the use of lesser gas and the engine performs accordingly, so yes you get lesser performance but I do not believe you can damage or hurt you engine if you went with lesser gas for a few weeks or something. I would of course never do that and would always buy what the manufacturers suggests but its not the end of the world if you accidentally fill up on lesser gas once or twice.

Edit: I was wrong, so ignore everything I said. lol

Even though you've already been corrected, there are indeed safeguards built into the car, but it's not meant to be an option to use regularly or even sparingly. The ECU will detect it once the engine starts acting up due to the lower octane fuel, and to prevent any further knocking or stuff like that, it will retard timing, which will allow the engine to run without any huge problems (though of course you will lose some power), but it's meant for the event of premium fuel not being available, as opposed to refusing to use it from that point onward.

Some people do tune their cars to utilize lower octane fuel in a safe manner, but again, it's useless to go through that hassle to save 20 cents per gallon at the cost of a certain amount of performance. But some cars nowadays will adjust as intended by the manufacturer. I know one of the Hyundais adjusts its hp and torque depending on the octane used, but in those cases, the "normal" octane to use is 87 while getting more out of a higher octane when used, not the other way around.

[russv]

12.5 compression ratio. Enough said.

[Turbowned]