Should I use premium?
 

I have a 88 10th ann. turbo II. The guy I bought it from said to just use regular pump gas. Should I be using premium?

I've actually had a similar question for my s5 turbo. Mines stock and I have been running regular fuel. Idk where it was but I had read I should use premium but I assumed BS.

I use name brand gas every time and I have never noticed a difference between using any of them... I know why they say you should use the higher stuff but I don't think its a problem if I am using good gas. Am I wrong? It just seems like a bunch of talk and no evidence or proof.

Its not necessarily true that all turbo cars require premium, its still a good idea to use premium regardless of what the manual says in a turbo rotary. A turbo rotary engine is absolutely intolerant of knock. In my own foray of tuning my haltech equipped turbo car with a knock sensor and egt gauge I found 87 octane to be significantly more knock prone than 91

Higher octane fuel provides just a little bit of additional safety margin therefore its worth the cost.

not exactly true. (in regards to two post above.)

odds are though the car in question isnt 100 percent stock. with that i would say go with at least 89. The FC will compensate for crappier gas to some extent if your lightly modified, usually in the form of lower power and crap fuel mileage.

but premium is a steal anymore anyway.

Wow!
 

This entire thread is full of mis-information!

First off, with the lower octane you can get away with the better! Lower octane will actually make more power! It has a higher power density.

THe only reason we have higher octanes is due to knock. THe octane rating is actually a measurement of the resistance to pre-ignition. THat is it! It is not a measure of being "better, or more powerful"!

Stock FC's (Turbo or not) are to use regular 87 octane. Only if you have alot of modifications, or are running retarded timing, do you need a higher octane!

Thank you! this is exactly what I supsected lol. Engine wise my car is stock turbo except removed rats nest and a Redom chipped ECU. The turbo is only hitting about 5 psi instead of 7 so idk but I think I am safe. I am 90% confident that the reason the manuals say premium is because they cant tell you to only fill up at such and such station. So if you put crappy gas in then you want premium at least.

I run 87 on my stock S5 TII.

You've got a chip, then you need premium. Any chip that was designed for the JDM would be designed to take advantage of jap premium which is what 95 octane.

Thats how its able to give you more power, by running closer to the edge advancing the the ignition, and running a little more boost.

The car has been running on regular pump gas for 20 years. That should tell you something, lol.

Are you trying to get banned by posting bullshit?

I don't trust you because I have read the manual and you obviously have not.

^ This is generally true.

Shouldn't I notice a difference when using higher octane gas? Seriously couldn't notice that I had different gas in the car.

Well whats the mix rate if u still have the omp because i had a 87 b4 and i did not have a omp so i did 1oz - 1gal but now i have a 91TII with the omp what mix should i do???

Its a car that has an engine, it takes gas, so put some in it...?

Everyone has beliefs in certain types or different brands of gas...
"I only run v-power, its awesome."
"my car only runs on chevron, thats all I've ever put in it."
"I use premium gasoline because it makes my car faster."
"My car doesn't like cheap gas."

If it runs fine on regular. run regular. if you get knock or detonation on regular, pull your timing or lower your boost, or run higher octane...

Gas doesn't make your car faster or better, unless your running 110 octane w/ 30psi...

posted by Icemark:

Anything more than 87 octane on a stock FC motor actually is more likely to cause problems, and will actually result in less HP.

See the octane rating has absolutely nothing to do with BTU or power output. The only thing higher octane numbers do, is make it harder to pre-ignite. It makes the burn slower. Higher octane does not contain any additional power or performance unless the motor was designed or tuned to run on a higher octane (and even then the additional power is only a result of higher compression or boost along with computr processing).

In fact (more so on a non-turbo) you want the gas to ignite as easy as possible. Lower octane on a rotary with less than a 10:1 compression actually burns cleaner and faster than a higher octane.

So using higher octanes on a stock motor will result in increased deposits on the rotor faces(which could result in pre-mature engine failure), less power, and less money in your wallet.

So why would you waste the money and buy anything but 86 or 87 octane

He has an RX7 not a Volvo or Audi. You are not nearly as smart as you think you are. If you are running stock boost put regular in it.

Mazda designed the car to run on regular. Stop spreading misinformation.

Because the factory manual for the turbo FC specifically states that you can run 87 octane and also has a caveat for 10 percent ethanol blends.

OPs car is STOCK so any answers that consisted of "RUN PREMIUM THE MANUAL SAYS SO" are completely incorrect.

Here is your quote in case you forgot... Completely wrong.

I was about to snap until you posted. The people above you don't know shit.

Mazda says 87 octane for the turbo.

If your car is bone stock run 87, if its turbo and has some aftermarket support run a higher octane. I run 89 with rb rev tii exhaust.

Advanced timing requires more octane, not retarded timing.

Pump gas from a given vendor usually has about the same energy content regardless of the octane grade, so in that respect you would not notice any difference. The statement that "lower octane fuel has more power" is based on a pure octane/heptane reference mixture, which is a standard of measure and not an actual fuel that you can buy. Pump gas can be composed of many different comonents and in many different proportions, so the energy content will vary between vendors, seasons, regional fuel regulations, and other factors.

The reason fuel companies can get away with misleading advertising about high octane fuel possibly increasing performance is based on the premise that a car's knock sensor would retard the timing under light knocking, decreasing the performance. However, this is based solely on a situation in which the engine is knock limited by the lower octane fuel, which is not a factor for a mostly-stock 13B or 13BT in good running condition.

If the OMP is working then there is no point in worrying about it.

What is up with these guys? Is there a full moon out there or something?

BMW, Mercedes, or any high compression motor can require premium. It does need a turbo to take premium.


Also, this is about a turbo rotary, not an Audi or a turbo Volvo.

I just put down 240 at the wheels on a Dyna Pack at 11psi.
Stock turbo, stock intercooler, stock fuel pump...
Details posted in the Time Slip and Dyno sub section.
Fuck high octane! :D


-Ted

And that right there ladies, is your proof. I am assuming this was done on 87 oct.?

Yes, details are in my thread in the Time Slips and Dyno sub section.
I forgot the car had the low octane stuff in it, since gas prices are just dumb.


-Ted