use regular gas?
 

I went for a test drive over the weekend (FR-S) and stop by the gas station for a fill up. I saw the sales guy reached for the cheapest gas and i pointed out to him the gas door label says "Premium gas only" and he responded that they put regular gas in all their cars (even the higher end Toyota V6 engines).

Is it ok to put regular gas instead of following factory recommendation?

No

If you want your engine to knock, which causes considerable stress and can ruin it keep using regular. i would never go below 91 octane. The warning label is there for a reason.
The sales guy isn't buying your new motor...........you are.

Maybe I'm just paranoid, but I wouldn't buy from a dealership that I know didn't put the correct fuel in the car. It just shows that they are cheap and care more about saving a few bucks than properly maintaining your car. The fact that the salesman was so open and unashamed of this behavior also shows that he knows little about his product.

Unfortunately, most dealerships probably do this exact same thing. Bastards.

i wouldnt be surprised if it can take it just fine but runs in a safe mode of some sort

yeah, I wasn't comfortable buying my car there.

Knock=BAD

No safe mode on the BRZ

report to Scion/Toyota manager about this, Id prefer not to see threads in the future of people coming off the lot brand new with already deteriorated performance from damage that could have been potentially caused by improper use of petrol.

I dont blame your sales rep that took you on a drive. considering they dont train for this sort of thing, and its less likely that they have any experience with sports/performance cars let alone one built from an entirly different manufacturer (Subaru).

But that doesnt excuse them from not being educated if they arnt already. So report your experience to manager and make sure all Scion FRS at that dealer needs to be treated properly.

-Josh

i think he would have mentioned if there was knocking

The label on a bottle of bleach says do not ingest.

But go ahead and see what happens.

just about every single aftermarket part for these cars say they are for offroad use only.

but go ahead and see what happens

Actually, they don't, unfortunately for your argument.

For example, I only buy exhausts that are under 94 dB and marked as street legal (my preference would be Greddy exhausts, almost all of which are legal, including the FR-S one).

Same with intakes, which you can differentiate between those that are primarily for track use and those that are safe on the streets (AEM vs Injen, though both are street legal; AEM still in production, however).

Many performance headers are also 50-state legal (no word yet on Agency Power, but DC Sports are often street legal whenever that header comes out).

And tunes. Those are definitely legal.

Regardless, you made an ignorant assumption that I run off-road parts on a street vehicle and it sort of makes you look like a dumbass.

Thank you for your time. Please try again next time.

i never assumed anything about any of your actions. take it easy. im just making a point that labels arent the be all end all.

Premium non-ethanol ONLY!!! It makes a huge difference. :burnrubber:

I have a place here that sells 89 no ethanol... Or I can get 93 with... I hate it.

I think my car had 87 from the dealership. After my first fuel up, it seemed to wake up the engine a lot. I'm not sure if the reason for poor initial performance was a break-in issue or 87 octane, but it's had nothing but 93 since then and runs great.

Also, after switching to Shell gasoline, the bird chirping under the hood is all but gone, which was a nice surprise.

Using 87 will not destroy your motor or cause it to knock. The manufacturers suggest 91 because it is tuned to the advertised hp/tq/mpg numbers at that octane rating. The factory knock sensors and O2 sensors will tune down your timing and other factors to run on 87. You may not achieve the full 199.9hp on the FA20 but it will not damage your car.

In other words, lower octane will decrease performance but not be detrimental. Would I run it for the long term? No.

If you do not want problems with your engine down the road, do not put anything other than 93 gas in this car. It will probably survives for a year other two on lower octane fuel. But if you plan to keep it longer, follow user's manual, which states 93 only. And pass on any gas with ethanol content over 10%, it is not compatible with FA20 engine either. Welcome to the world of real sport cars, where you need to do something special just to be able to use them daily.

Cars that have this sensor actually say in the manuals and some advertisements that one can change octanes, this car does not mention any sensor and advises no less than 91.

This car already under-performs on 91 octane fuel. Anything less is seriously risky. With 94 E10 it seems to run fairly well.

Stay away from ethanol, that cherp is rather annoying. Its not too hard in jersey to find 93 w/o ethanol thankfully.

Just don't. The engine will pull timing in order to run on it if your only option were to run regular fuel, but you should never do it unless it is a last resort.

Then I guess all of us here in CA are in trouble with our 91 octane gas ;)
I know what you mean. Lexus is one that advertises using different octanes. Though, just because they don't advertise it it doesn't mean it won't work. Take some time to read up on Long Term Fuel Trims and Short Term Fuel Trims. It might help folks draw their own conclusions.

Again, would I do it? No. If it was half the price as 91 I might because i'm not at redline on my commute to work and will not benefit from the added octane as much.

Slightly off topic... What is the highest octane fuel you can benefit from on a stock tune?

I'd be surprised if a high compression engine such as the FA20 didn't have a knock sensor. So the risk of damage to the engine from detonation is probably slim.

Still, it's obviously not good for the engine in the long-run and you'll get worse gas mileage with the lower octane fuel.

Yes you are.

I feel like i get worse mpg just using fuel with 10% ethanol in it :|

You do. I kept track of how much I got out of each tank. Shell 91 Ethanol free gives me between 7-10% better mileage than 94 10% Ethanol. But 94 definitely feels snappier and I get better throttle response.

Excellent! New car for me (and my other CA brothers) in a few years from Subaru & Scion :thumbup:

I got 38mpg on the highway with 94 Octane E10 in my car. Just saying.

pretty much every dealer puts 87 octane in everything because they are careless morons. It isn't the best for the car but it won't really matter either. Once it's yours, put 91+ in. Before it's yours, just pretend all those crappy fillups never happened.

..... I live in Iowa..... Everything has ethanol


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I dont think 87 will hurt it at all, I had a 1994 Supra Stock motor, requires premium gas, I bought the car is 1998 and I only used 87 octane in it, runs fine and no knocks and I had over 200,000 miles on it when I sold it a few years ago.

But with the High 12.5-1 compression ratio i wouldn't use anything less than 89.

THIS is the correct answer.

Ditto! My step father works for Toyota at the National HQ in Torrence, CA, and is one of head parts managers. He stated the exact same thing as RYU did. Scion legally has to say only use whatever octane was used to get the performance and MPG numbers. It wont hurt the vehicle at all but could possible deminish performance and decrease MPG slightly. Everyone else are idiots and clearly have not done their homework. :slap:

With nearly 12.5:1 compression...Premium Fuel is the Only Fuel I will use.

Found some info in the manual published by Subaru on the BRZ.
●Use only gasoline containing a maximum of 10% ethanol.
DO NOT use any flex-fuel or gasoline that could contain more than 10% ethanol, including from any pump labeled E15, E30, E50, E85 (which are only some examples of fuel containing more than 10% ethanol)
●If you use gasohol in your SUBARU, be sure that it has an octane rating
no lower than 93 AKI.
●●SUBARU DOES NOT recommend the use of gasoline containing methanol

■SUBARU recommends the use of cleaner burning gasoline
Cleaner burning gasoline, including reformulated gasoline that contains oxygenates such as ethanol or MTBE (Methyl Tertiary Butyl Ether) is available in many areas.
SUBARU recommends the use of cleaner burning gasoline and appropriately blended reformulated gasoline. These types of gasoline provide excellent vehicle performance, reduce vehicle emissions and improve air quality

■Fuel types
Unleaded gasoline (93 AKI [Research Octane Number 98] or higher)
If unleaded gasoline with an octane rating of 93 AKI (98 RON) is not available,
unleaded gasoline with an octane rating of 91 AKI (95 RON) may be
used with no detriment to engine durability or driveability.

Thank you! Great Information! Clearly You did your home work!

If he knew what he was talking about he would have told you that anything under the 93 octane will 'definitely' diminish performance and also reduce fuel economy, not 'possibly'.
The engine is detuning itself to cater for the lower octane in proportion to the level it needs to go to avoid damage. It was never designed to run like that.
Have a word with someone in the service department instead of spare parts.

Has anyone got some dyno figures to show how much power is lost?

87 octane will not cause knock...but 87 octane is more prone to knock. This starts to become more serious as compression rises..and at 12.5:1 CR..its a number thats enough to worry about.

short term knock wouldnt worry me, and the ECU will pull enough timing to compensate. But its another matter that the wear and tear of the internal components of the engine are already accelerated before the car even has its first owner.

detonation is detonation regardless if its big or small, and id prefer to know that when i go into a dealer, the car is in tip-top shape.