What gas u use????

[Khmai G]

I always put 89 octane gas ever since i got my tc. I heard it makes your engine alot smoother. So i did a test, i filled my car up on regular 87 octane. There was a diference, the 87 seems to make my engine run kind of sluggish. It wasnt as smooth as the 89. Do any of you guys run 89? Does 2 points of octane really make a difference? I always put Cheveron or Shell gas.

[Redneck4csa]

Navy will tell you to use 87 as that is what the car was originally set-up for. I have always used 89 in all of my vehicles. I think it improves my gas mileage somehow. I could be wrong, but that's just what I've always used. I won't put 87 in my baby.

[SquallLHeart]

i use 87 because unless you're boosting.. you don't need a higher octane.

as long as you stay away from crappy non top-tier gas brands.. you're ok.

[GovTC]

I uses 87 as well. In the dirrerent companies that i have use weither it was BP, Chevron, Mobile, 711, Citco, and shell to name a few it has always been 87. What i have noticed was that with the different companies i used and putting in 87 everttime my car would run different. It could all be in my head but iffelt like she didnt have the pick up and go or she just didnt want to move. The best company that I have found and use mostly is shell using 87. Not ll gas stations use the same addative in there product. I have found that while I was going to different shell station i still got the same result. which was she had more pick up and go. To get back on topic Sorry about that. Putting in a higher octane, Unless you have a turbo I dont see the need. and about getting better gas milage I couldnt tell ya. But I will give it a shot with all three grades. I will try three different companies with three different grades. The companies I will use are Shell 711 and a place called WAWA. and I will let you all know. Info on my car It is an 06 5speed the only thing i have added was CAI Injen. we will see if there is a difference

[navylife59]

Remember that we have a learning ECM. This will allow some minor adjustments to timing and VVT-i engagement based on driving, atmospherics, fuel quality, and emissions conditions. Two exact mileage tC's running the same fuel in the same conditions could have very slight differences in engine operations. Tolerances in sensors and learned tables in EEPROM can cause differences. Another thing to take into account is that the engine is striving to keep stoichiometric 14.7 A/FR. Running a higher octane fuel is going to see the motor pulling timing to keep stoichiometric. That equates to less power.

Higher octane fuel has a less affinity for explosive combustion (slower burn). This is important in higher compression, blown, Nitrous, and motors with extremely advanced timing (think old school distributor on this one). The additives that make the gasoline higher in Octane does so at the cost of BTU's. Lower Octane has more energy (calorific) potential, thus, has more affinity for combustion at a faster rate. Lower Octane equates to less timing and less power. High Octane equates (assuming the ECM allows it) to timing advance and more power.

In the old days, you did get more MPG running higher Octane fuel. Motors back then had higher compression, mechanical timing advance, and inefficient cylinder heads. The higher Octane allowed you to tune your engine to it's best efficiency. Forward to today's vehicles with their higher efficiency and computer controls. The emissions standards built into the ECM is not there for MPG. It is all about reducing emissions. This is where companies like UniChip make up that magical boost in MPG and power.

[Khmai G]

Ok, got cha!! Chevron all tha way!!!!

[ACE-tC]

i use 89. ive noticed that the 89 for me drives smoother and lasts longer than if i were to use 87.

[SquallLHeart]

yea.. but did you read this??

Higher octane fuel has more energy per cc which can provide a slight increase in MPG but you have to measure that gain against the added cost.

is the small amount of mileage added worth it? most times.. not really.

here's more stuff to read..
The Low-Down on High Octane Gasoline
The Truth about High-Octane Gas

[navylife59]

All you need is 87 Octane and a large can of Red Bull. Justr Kidding!

[SquallLHeart]

well.. you could just use an entire case instead..

[navylife59]

That is kewl. Thought that I was the only one out there!

[CadenceScion]

I've owned my 2006 Scion tC since Nov of 2007, and I have always used 89 or 93 octane. I don't believe in using 87 octane due to the fact it burns faster, the idle isn't smooth, and hesitates when the throttle is wide open. I find I get more miles per gallon, better idle, smooth acceleration and much better performance with a higher octane. I have talked with some mechanics and most have said running a higher octane won't hurt your engine, but it will also allow for better performance, better gas mileage and less carbon build up/deposits/gum/varnish...etc. Ever since I was old enough to drive, I have always done the math when it comes to fuel mileage and I am sorry to say a calculator doesn't lie, I have been getting on average of 2-4 more miles per gallon on 89 octane, plus I have noticed I don't burn the fuel up as fast as I did with 87.

I have found that running a lower quality name gas, like HESS, Valero, QuickWay has given less mileage and less performance. I stick with fuel that I know gives me the best milege, performance like Mobil, BP, Chevron, Shell, Citgo, Kwik Fill. A lot of people think all gas is the same, but this is not always the case. Every gasoline manufacturer uses different additives/cleaning agents and not all of them will repsond or burn as efficently as others. In some states most gasoline being used has Ethenol/E85 in it. Most cars on the road today aren't designed to burn E85/Ethenol, and it has been causing more problem than you can shake a stick at. Mechanics/repair shops are dealing with numerous customers coming in with check engine lights, poor acceleration, spit and sputter and other misc issues. With E85/Ethenol you will lose some performance and also gas mileage. I have also heard that it can eat away at seals, gaskets and other parts. Another bad part of E85/Ethenol is that your not supposed to use any fuel additives/cleaners. I have to say that I have been using fuel additives/cleaners for years and have yet to have any issues. My engine runs great, idles very smooth and performance is always there.

Athough in this case and wth this discussion would be a great topic to bring up with the " Mythbuster ".

[CadenceScion]

To elaborate further more on different octanes, not every car manufacturer responds the same to higher octanes. In some cases in may take a few tanks of a higher octane to see the fuel mileage, performance and acceleration increase. Plus with this being said, not every cars computer is built the same either and the sensors, mapping system, Air/Fuel Ratio, and other areas will will not respond the same to a change in octane. My girlfriend and I also have a 2005 Hyundai Tiburon GT, and we both refuse to use 87 octane. We have noticed with the Tiburon GT that 89/93 octane responds better than the 87. We have also found that Mobil 89/93 gives the Tiburon the best MPG over Sunoco, or Kwik Fill. With this being said and keeping this thought in mind, not everyone lives or drives at the same altitude either. A higher altitude will result in less air and more fuel which results in less mileage and performance and vice versa. Some vehicles do require a certain octane rating based on how the cars are built, tuned and designed. With BMW, Audi, Mercedes-Benz, Acura, VW's, Cadillac, and some others for example require a higher octane, but most I have found ignore what the manufacturer says and run 87 octane. In my opinion if you can afford to drive such an exspensive car, you should be able to afford the correct fuel it requires. Some car dealers and car manufacturers will void a cars/trucks warranty if you do not use the correct fuel it designed to use, this I know applies with most BMW's and other higher end luxury cars/SUV's.

This past week I waited on a guy who owned 2009 Porsche Cayenne S and pulled up to gas pump and asked for a fill up. Would you believe the guy who was driving the Porsche Cayenne and had to have paid somewhere in the ballpark of $80,000 put 87 octane in the tank. My eyes just about popped out of thier sockets. I pointed out to the guy that his fuel door said minium octane rating of 91+ and not 87 octane. He said this was his third Porsche Cayenne and it runs just fine. I walked away with a disgusted look on my face. You buy an $80,000 performance machine and put 87 octane in the tank, what the hell are you thinking? He wants to ruin his engine and his warranty, that is fine by me.

[navylife59]

All the lower tier gas chains buy their fuel from the same source. In the old days, the station manager had to add the additives to the station's tanks via large drums. Nowadays, these stations can request the additives they want in their fuel when they order it. Do you know how fuel gets piped from the refinery to the distribution centers. All grades of gasoline, including diesel, are piped in one large pipe in batches. The interim mixes between the batches is supposed to be captured and sold for a different purpose. I hazard to guess that this sub-standard gas is making it's way to low-end, value retailers.

[pilot941]

I use 93 with a bone stock car. I do notice better fuel economy. I wouldn't mind running 100ll, because there is no ethanol in that, but that may be a bit much for that car.

[Techman]

The TC is designed for 87 octane so that should be used for optimum performance. Using a higher octane is not helpful unless your engine has a higher compression ratio (usually 11:1+). Otherwise, using the lowest octane possible is the best idea since higher octanes do not burn as readily. I run 91-93 octane on my 300zx because I have to in order to keep it from detonating. I am also running it with the timing advanced slightly. On the TC, I would never spend more money on gas to lose performance.

[navylife59]

Higher octane fuel has a less affinity for explosive combustion (slower burn). This is important in higher compression, blown, Nitrous, and motors with extremely advanced timing (think old school distributor on this one). The additives that make the gasoline higher in Octane does so at the cost of BTU's. Lower Octane has more energy (calorific) potential, thus, has more affinity for combustion at a faster rate. Lower Octane equates to less timing and less power. High Octane equates (assuming the ECM allows it) to timing advance and more power.

In the old days, you did get more MPG running higher Octane fuel. Motors back then had higher compression, mechanical timing advance, and inefficient cylinder heads. The higher Octane allowed you to tune your engine to it's best efficiency. Forward to today's vehicles with their higher efficiency and computer controls. The emissions standards built into the ECM is not there for MPG. It is all about reducing emissions. This is where companies like UniChip make up that magical boost in MPG and power.

[mark_hou]

i say 89 and up

[vinny719]

whit the price of gas going up i use the cheap stuff

[navylife59]

It is all the same base gasoline. The differences are the additives. What you have to be careful with is the transport and storage. Most discount gas stations utilize private trucking to tanker their fuel. Some of those tankers don't look in too good of shape. Not sure if and when any inspections are done by the State on those tankers. Additionally, the discount gas station themselves are usually at a location that has been there for decades. Their pumps, lines, and tanks may not be the best environment for storing/dispensing fuel aka contamination. They are regulated by the State and subject to inspection but I do not know what the criteria is for the life of the storage tanks. Rule of thumb, if the gas station is old and you do not see new style (credit card) pumps, then steer clear of the place. You can also ask them when have they replaced the filters on the pumps.