Gas Premium or regular?
 

Hey guys

Just to clarify something here, as we all know the engine under this car is a boxer engine, when i was ordering my FR-S, the guy said this car can run on regular gas if you wanted too.I think he was mistaken with the other Toyota cars. However the question is would you run it on regular if gas price goes sky high lol.

manual says premium gas only.

Read your owner's manual. It requires Premium.

Don't worry about the price. Premium is usually only 20 cents/gal more than regular. That's only about $2 per fill-up. A pittance to pay for peace of mind.

91 or higher only. If nothing but 87 was available i'm sure it would run but I wouldn't drive it aggressive at all. Stick to premium

Premium is required, but it will run on 87, as will all cars that require premium, if it HAS TO, like in an emerg situation, like if you in the middle of a nowhere gas stop and all they have is 87. The computer will adjust the timing to accommodate the 87, but, BUT, it will run like crap, have less power and get WORSE mileage. The money you think you're saving by putting in 87 gets eaten up right away in getting less per mile so you're not saving a damn thing and potentially costing yourself more in the long run if you run 87 regularly.

If putting 91 or higher is a problem for people, them why even but the damn car? These kind of people remind me of the old quote "...those that know the price of everything, and the value of nothing."

^Bingo. It amazes me every time this question is posed. Not because it's a dumb question, but because who wants to willingly degrade the quality of their car?

Lovingly hand-washed weekly or gas station auto-wash once a month?
Oil change every 6k miles or 60k miles?
Properly inflated tyres or whatever pressure they happen to be at is fine?

There are loads of ways to expedite the wear and tear on your car, over and above the fuel you use. Use you imagination!

The premium grade available in New Orleans is 93 octane but the majority of them have 10% Ethanol. Personally I use pure gasoline by looking for gas stations listed here http://pure-gas.org/ It's a matter of preference and I'd like to have the most energy-efficient burning gas available for my beloved car. =)

Thanks for that. Disappointing there's not one station listed for Houston.

Actually.. The car can run just fine on regular unleaded. I have noticed that many performance cars today have no issued running on reg unleaded as the computers adjust the spark, timing, etc... its really not that big a deal unless you are looking to race the car.. normal driving.. there's no difference..except to your wallet. The only time you will notice a difference.. is if you use racing fuel.. at like 104 octane.. I used that in my mustang of years ago.. and it definately made a difference.. also made the whole car smell like gas..lol.. it was actually pretty cool back then

My bad i forgot to mention it's a user submitted website so not all ethanol free gas stations would be listed. They're typically smaller non-corporate mom&pop gas stations. A quick google search for houston ethanol free gas stations brought up a number of car forum threads asking the same. I'm sure you'll find one near you easily. I didn't realize the one 3 blocks away from me was ethanol free. It looked like a tiny abandoned station with alcoholics loitering about. I only want to the Chevron 10 blocks away only because it was 10 cents cheaper. Goes to show you that looks can be deceiving! Don't dismiss that small dismal looking gas station! They're typically the ones that close at 8 or 9 after the megamillions time cutoff!

Most Toyota models that specify "Premium" are typically looking for 91. The FR-S manual is looking for 93.

Jeff

To answer your question, yes regular will run but why risk damage to the engine to save a few pennies.

No damage will occur. Just less power. Use whatever you want to use - regular or premium or plus. My father has always used regular gas in his Acura MDX for the last 10 years since new and the car's been running with no engine or power train related problems. It now has over 150K miles.

To which I's ask, does the MDX manual say premium recommended or required like the FR-S manual? It's understood that if it says recommended, then using regular will have no real effect on mileage and is ok, but you will lose some performance which for daily driving is fine.

But if the engine REQUIRES premium, as the FR-S does, then you will be getting worse gas mileage, negating your savings and worse still, putting you in a precarious warranty position if your problem is ever fuel related.

Personally, I'm no gambler with my money and do what I can to get the most out of the car, and keep me in good graces with the factory warranty. If you feel that's all hogwash, feel free to be the guinea pig, since it's not my money/car on the line.

Crimony, can somebody just put this to bed already. The car wants premium, give it to her!

If you don't want to use premium, don't buy the car.

I would stick to premium as stated in the manual. When I was working at the dealer before (BMW), we had a lot of customers that would be cheap and put regular instead of premium. More often than not there were a lot of fuel related problems. Despite us telling them the cause is the gas they continued to ignore it and use 87. Needless to say they weren't very happy when warranty would get denied due to improper fuel.

Not necessarily. Just because it can be done doesn't mean regular will be "fine" on this motor. Also using higher octane won't do shit, unless the car is tuned for that octane...

I think that website needs its own thread sticky. That is a great piece of information.

:thumbup:

Wow, in the northern Virginia / DC area there is not a single gas station listed. Everyone gas station uses the blend

The knock sensors can only adjust so far. Technically it's rated for 94 at sea level so running 91/premium already is pulled back a touch. Run 87 or 89 and you might be pulled as far as possible leaving NO wiggle room if you get any bad gas, or any sort of other condition that would pull timing. So you'll knock and damage the motor.

If 2-3 bucks a fill scares you, do not buy this car. Get a Fit or Elantra or some other 40 mpg car tuned for regular.

Again the website is one of many user submitted lists of pure gasoline gas stations. I did some random googling and found out that boaters are very picky about what gas they use on their motors. Fishing enthusiasts usually know where all the pure gasoline stations are at that aren't posted online. Check your state if it has a mandated requirement that stations have to have a "may contain ethanol" sticker on their pumps!

How many people got 87 in the tank on delivery? all my toyota dealership had in stock was 87. When I noticed them filling it up they said they had to let me leave with a full tank of gas. I asked them to stop but by then it was almost full and they said "these cars have oxygen sensors that compensate for the lower octane" I wasnt happy about it but one tank of 87 should not cause a huge problem. That being said. How many people probably got a car with 87? Prob alot.... because at the 2 dealers I went to only had 87 on their pumps on the lot. So buyer beware. You probably are getting the first full tank filled with 87. Really not a big deal but would have loved to be able to get the ball rolling on my terms. :) food for thought

My salesman told me he took it off the lot to a nearby gas station and filled the tank with premium (93 octane). They were doing that with all the FR-S.

The engine is over 12:1 compression and you want to run regular?

It is a bad idea. Yes, it has 2 knock sensors and will do its best to adjust when you use regular, but it will have to pull timing and add fuel to lower cylinder temps. This will cause lower power and worse fuel economy. It will also void your powertrain warranty if you crack a piston ring or ring land from detonation and they bother to get the fuel analyzed

^^^^^exactly! So make sure you watch what fuel goes in. Word of mouth is just that. You never know what can happen when someone is rushed, swamped swamped swamped, while trying to make sales. Be proactive not reactive.

My dealer mandated that we fill all our cars with 87 octane when they require premium ... Makes me cringe. I know they'll be fine for the first few hundred miles (states in the manual that it can be used at the expense of decreased performance), but it's just so petty. Fill the high-compression, often forced-induction engine with 87 swill just to save a few bucks tops? And how good is that gonna look on a test drive when the engine pulls timing and accelerates slower, making the driver think it performs at less of a level than it's really capable of? Stupid.

Of course they do, but that doesn't mean the car doesn't REQUIRE min 91 to run at optimum performance AND fuel economy. For a car that requires 91 min, running 87 isn't going to save you $ since your mileage will be worse.

Don't forget, 99% of dealers and employees are not "car" people; this is just a business to them and they couldn't give a crap about the engineering and care taken in developing these cars and the people who appreciate and enjoy them. To them "gas is gas".

12:1 compression, as has been stated already, requires a higher octane to prevent chance of detonation/knocking. Knocking = damage to your engine, ranging from cracked piston rings to bent rods, and that is never a cheap fix. So, suck it up and get premium gas.

Also, from a lot of research I did after getting the S/C on my tC, "premium" = 91 or higher. As we say in the engineering world, K.I.S.S.--Keep it simple, stupid. Fuel your car with at least 91, maintain the recommended maintenance, and don't drive like a complete idiot. :)

My dealer took me to the gas station on my test drive and he filled it up with 91.

Mine too. In fact, they didn't fill it up until after I bought it because they didn't want to put any miles on it.

Brett

Yup - and to be clear I said "over 12:1" The FA20 has a 12.5:1 compression ratio. The reason for my wording however, was that I would never put under 93 in a 12:1 car unless I had no choice (Cally, Oklahoma) where I would get the highest possible octane and quality

My salesman confirmed that it needed premium, and then went across the street to fill up. Bibin Thomas at Ft. Bend Toyota is great at his job.

I won't believe anything written here until someone shows me a damaged engine due to using 87 oct gas in any gasoline engined car.

Why not just read about what an octane rating actually means? It's not that complicated. Using 87 on a high compression engine is like putting gasoline in a diesel engine, but to a lesser extent. In fact, read the how stuff works article on the diesel engine and that should help you understand.

i hate our stupid state of CA. stupid Environmentalists and the Left movement have ruined our gas too. only 5 in the entire state have no Ethanol - im sure its down to 0 by now.... sucks - i remember buying 95octane or 100 in some places in the early days..

With GDI, it's not as critical as detonation is less prone on 4D-S as ignitable mixture is not present in the compression cycle. However to advance the injection timing and ignition timing by engine and fuel system EFI mapping, the 91 and higher does exhibit and is needed for catalog specifications. It will run on 87 and I've already tested it... Dynamometer showed 11hp decrease, possibly due to the delays it needs to inject the 87 safely into a 12.5:1 compression chamber. But no pre-ignition (knock) was detected and it ran flawlessly as such for a full tank at 87 as well.

Thanks for the info. Good to know

Question. I'm a Shell user and their Premium gas tops out at 91, but no ethanol. Now Petro-Canada branded stations(They are a Suncor brand) offer their Ultra Clean premium at 94 octane with ethanol. Which overall would be a better gasoline to use.

Realistically, I think all major brand pump gas exceeds the requirements for what Toyota/Subaru has tested in reliability. I don't have the numerical data for the fuels, and vast majority of the difference is actually in your locale and season, as they mix different levels of detergents and anti-contamination agents for climate changes both in shipping and usage. Also some ill-maintained gas stations have rusty tanks that contaminate the gas in different levels too.

The best gas I found is to always seek a well-funded and better maintained gas station, who maintains, cleans, and calibrates the pumps and tanks, and to stick with desired gasoline octane that fits your needs and the recommendation grade for the car.
Again, however, GDI has very sophisticated timing of the injectors and operates very differently than traditional port-injected engines, and therefore, we'll see in due time, when people do more testing to see which gas the FA20 likes...in terms of making power, compatibility with ECU, and parameters that is specific to the really complex firing of 4D-S system.

Based on what I am seeing here, you likely wont. What you do see, as has also been pointed out, is a lower power, more sluggish engine. The nice part about modern engineering is that it helps to make cars more idiot-proof. :bonk:

So, by all means, you may go ahead and save a few bucks and use 87, but please don't complain about the car being sluggish. Also, to my knowledge, there has been no long-term testing with 87. I would guess that running a below-recommended-octane fuel will likely lead to a premature buildup of sludge and carbon in the engine, since the retarded timing would seemingly lead to an incomplete burn.

Feel free to correct me on any of this, guys :slap:

I didn't expect this thread to be this informative lol. However i'm gonna stick to premium fuel as what the car was supposed to run as. I just hope when i get my car, that they didnt put 87.