i have an 08 ss and i no that premium fuel is recomended. but dose that mean that regular will mess up the valves in my car? because i had a friend that bought a brand new 5 series bmw n put regular gas in it n messed the car up. is there any hp/tq difference between the two?

 

my guess is your friend didnt read his owners manuaL? For our cars you should always run premium, especially since it has a turbo on it. There are already alot of reasons listed else where in this forum why you should use premium over the other stuff. search it.

p.s.-87 octane will run in our cars but you will eventually get engine knocking and have to end up replacing damaged valves, retainers, valve springs down the road. I would think to beable to use 87 octane you would have to lower the boost to like 8 psi.

 

When a manufacture recommends premium you should run premium gasoline...Its that simple. They dont choice on this car, lets go w/ PREMIUM to make them spend extra money for gasoline. The designers realize premium fuel is designed for cars that have higher compression. Under boost our cars have high compression, thus we need premium. With out it the engine will knock/ping (also known as detonation) as mentioned, this is caused the unexpected detontation of fuel particles under pressure, and not at its intendend time. Now our engines are advanced, and will see this happening, when they do the cars going to pull power, and timing to adjust for its not so wise driver, by reducing the pressure in the cylinder, eliminatin the knock, your car now has less power and is getting less mileage. But there is that small that percentage that will not care, continued running of a high compression engine while its knocking (adjusting for its driver), engine components are going to heat up, eventually this could lead to a worse known issue of preignition, which is the ignition of the fuel/air by the heat of the cylinderwalls or some other overheated source (plugs, carbon build-up, pistons themselves..you get the picture..your engine is freaking HOT). This will destory your engine.......

Its your choice though

 

You're not going to harm anything by running mid-grade fuel. It isn't going to hurt the valves and but it will cause detonation. As long as your car is stock the computer will read that on the knock sensor and adjust timing accordingly. This will have a fairly noticeable impact on performance. If you've modified the car, increased the boost, etc., then I would definitely stick with the pump premium.

Now as to why you'd want to run regular when you buy a performance car that requires it doesn't make sense to me when you run the math. Figure the cost difference in most places across the country between regular and premium is $.30 per gallon. If you drive 15k miles per year and average 25 mpg you'd use 600 gallons of fuel. That comes out to a difference of $180 a year, or $15 a month. Is that too much to spend in order to maximize performance in a car that you're already paying and insuring when you also have to add the expenses of tires, brakes, and oil changes?

If you're on a trip or accidentally fill up with a tank of regular don't sweat it. But otherwise most people should just stick with what's recommended.

 

ok premium only it is

 

If you don't plan on putting a high load on the car there isn't anything wrong with 87.

 

definitely what you need to run. Or else you will most liekly run into issues if you don't run premium. Plus, it's only a difference of like $4 from empty to full.

 

If you're driving a stock car the only "issues" you should run into are the reduced power. I personally wouldn't want to hammer the car while running regular but its not like the engine will blow up and drop out from under the car. There was probably quite a bit of drivability and calibration testing done to make sure it runs okay on regular. If not it would be required and not recommended, although even if required a manufacturer will usually make sure it will hold up on regular since some people won't run the premium and they don't want to pay for excessive warranty costs later on.

 

Just a note, I figured this out for another thread once. Premium versus low grade is a difference of about $200-250 CAD if you drive 20 000km a year. In the long run it's not really saving much money either to not use premium.


(I'm far too lazy to convert those numbers for you Americans, but you get the idea :P)

 

Just follow the owners manual and you'll be safe.

 

run premium, an SS is kinda like a performance car... and should be taken care of as such like.. following what is req by the manufacturer as far as fuel? Also the difference is negligible over a year.

 

u got an SS preimum only.....ur only talking 1 to 3 bucks extra a tank

 

Just as GM says...premium recommended...not REQUIRED...you will not damage anything by using regular. The computer changes the timing to retard any knocking and it WILL NOT harm the car...

 

Whats the point of having a fast car if your gas will only let you drive it slow? Stick with premium.

 

Wrong, I have seen knock on my completely stock vehicle at low RPMs. So with the LNF cars you must use premium or your engine is dying.

I will bet that even though the car is reducing timing it will stick knock or misfire quite a bit.

 

For those who are a little off as to why GM is recommending 91+ octane fuel, please read this link:

How Stuff Works: Ocatane Explanation

Basic summary:

1. It has next to nothing to do with load on the engine, its a result of the compression ratio of the engine
2. Your fuel economy will suffer using 87 in the LNF as knocking results, the ecu retards timing, etc.
3. Performance is going to suffer as the ECU retards timing which to me defeats the purpose of buying a "performance" level vehicle
4. Using 87 in "winter grade" fuel is even worse. Winter fuels are not on par with summer quality fuels for obvious reasons

Long story short, I figure if you invest in the car, you can invest in the fuel. It is of course personal preferene what you use but I absolutely refuse to use anything lower than 91 and for good reason.

 

yah im only running premium and thats usually 93 by me

 

I've been running 89 (89 ethanol enriched is a lot cheaper here in Iowa) in my 09 exclusivly, and even at 18psi its not knocking.... at all. I also appear to be seeing full spark advance. When I start actually using my HP Tuners to play with things then I'll switch to premium for sure

 

It's like an extra $2-3 dollars a fuel up.

I don't understand why so many people are so concerned with the "extra" cost of premium...

I'd use it just as peace of mind because it's what the cars manufacture that spent millions of dollars researching decided the car needed to run.

 

true

now what about the 2.2s out there.......there are many benefits to running premium but there has to be some trade offs.........or am i wrong?

 

?
I have a 2.2 and i ONLY use premium... i think ive only put reg in it a few times... but when i do, i notice mileage... but that's pretty much it. Ive got bad gas before, like gas full of water & so on... that causes the car to go CRAZY, missing, losing all power (what power it has, lol) not starting for 3 days in below freezing weather......... but that hasnt happened since...

 

Read up on how the knock retarding works...these new cars are pretty sophisticated...

I repeat...IT WILL IN NO WAY DAMAGE YOUR CAR TO USE REGULAR FUEL! If the car notices a knock or misfire, it will make an adjustment to the timing and you will be fine. Do you think it would adjust the timing for 5 seconds and then let to knock again?

Also, anyone notice the fact that the GM kit will come with a sticker that says "premium fuel REQUIRED". You think GM would have put one of those on the car from the factory if it were required...

Saying they allow you to put something in your car that will harm is it like saying they recommend you run 5 quarts of oil...no...they REQUIRE 5 quarts of oil to prevent damage...

All this being said, you will not have maximum performance form regular fuel...

 

Well doesn't it have to knock or misfire for it to pull timing.

It's an if then statement,

If knock or misfire

Then pull timing. It doesn't pull timing without provoking it.

 

http://www.cartalk.com/content/featu...questions.html

No clue how reputable this source is...but it seems to have some good info and supports the fact that a manufacturer requiring it is far different than recommending it...

http://www.cartalk.com/content/featu...ium/myths.html

 

I know how all that works the ECM has knock sensors in the block that detect knock. If they detect any knock the ECM immediately retards the timing so the A/F mixture has less time to burn that results in incomplete combustion ( poor fuel economy) and poor performance. Everytime it happens though the sensors have to see the knock first before the ECM can retard the timing so it is damaging to a point over the lifetime of the engine. Car runs like crap with 87 in it do not use it unless you have absolutely no choice. You have no business driving a turbocharged performace type car if you are not willing to pay an extra $2-3 to use premium fuel.