Gas Premium or regular?

[LeavingNormal]

Originally Posted by NeedsmoreCowbell

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

[Brett]

Originally Posted by LeavingNormal

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

[Boosted2.0]

Originally Posted by HunterGreene

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.

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

[Boosted2.0]

Originally Posted by NeedsmoreCowbell

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 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.

[miata]

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.

[dietz]

Originally Posted by miata

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.

[rikdrt1]

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..

Originally Posted by Enigmus

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. =)

[Moto-P]

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.

[moniz]

Originally Posted by Moto-P

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.

[Moto-P]

Originally Posted by moniz

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.

[HunterGreene]

Originally Posted by miata

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.

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.

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

[Dragon86]

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.

[Boosted2.0]

Originally Posted by Moto-P

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.

Knock was detected or you wouldn't have lost power. It wouldn't have been audible to you perhaps, but that is the whole point of the new 2 wire high rez knock sensors.

If you view the datalist and look at knock feedback value and knock correct learn value and ignition advance compared to a car being run on premium you can clearly see the differerence.

[smbrm]

There is another point to made here. The octane requirement of an engine does increase slightly over time and then levels off at a stabilized requirement, usually around 25-30k miles.