Any of you 2.4 guys switch over to synthetic? I'm gonna need an oil change here real soon and was wondering if I should switch to synthetic. I use 93 every time. I like to keep my car running it's best, and I'd imagine that synthetic couldn't hurt. If I did use it, I'd just use the Mobil-1 like the sc's. Will this show any signs of performance at all, or just smoother operation? Thanks!

 

the dealer that sold me the car told me to use synthetic. he also told me i could run E85 gas though. so im not sure. i plan on using synth when i change my oil. i run 87 gas :-/

 

I did not notice much difference at all,and as far as my oil life monitor,its going down at the same rate as regular oil

 

The oil life monitor doesn't know what type of oil is in there; it does its calculations based on cold starts, rpms, etc.

The way I drive, my oil-life monitor might not reach 0 until about 10,000 miles, so I'm thinking if I switch to synthetic, that may be a good interval to switch at. I haven't decided yet.

 

im running synthetic and seems to run smoother

 

same here

 

Cool! Thanks guys!

Since my car is still using regular oil, should I let a shop do the actual flushing and application of the synthetic for the first time?

 

I am running Mobil-1 synthetic.

 

you don't need to flush it. sometimes folks with high miles will, but you car should be new enough where it is not as issue. whenever changing oils what I would do is do the synthetic and then change it again, early. lets say, 5k. after that, use the DIC.

as always, if you drive hard, change more often than it says. personaly,, I do mine every 3k... but the way I drive, it takes MONTHS to get there.

bottom line, I have never seen a super high mileage engine where regular quality oil changes were not done. using synthetic is great when either high RPM or high heat is expected, but if it is your grocery getter. save the money and change it more often.

 

That's exactly why I switched to synthetic. Using the oil life monitor means I go longer between changes than I used to with other cars (in fact, I started to feel guilty and changed it when the monitor is down around 20 percent). I'm running Castrol Syntec, but don't feel it's better than Mobile 1. I guess I just like the paint job on John Force's funny car

 

don't use 93 in your 2.4 if you want it to run it's best

you shouldn't really notice anything when you switch over to synthetic, just that you have to switch it less

 

The only reason NOT to use synthetic is if you aren't planning on keeping the car. Everybody knows that synthetic is way better for an engine. It can make the car run smoother and can also help the gas mileage a little bit.

Also, DO NOT RUN 93 OCTANE! You will cause all kinds of problems by doing that. I wouldn't run anything higher then 89 octane unless you do some serious mods, like raising the compression ratio by adding turbo, SC or higher compression pistons. The reasoning behind this is simple - running higher octane fuel means it is harder to ignite the fuel. If the fuel is harder to ignite then you probably aren't burning all the gas in the combustion chamber efficiently which means less HP not more HP. Also since all the fuel doesn't burn it enters the emissions systems and exhaust, causing emissions parts to fail earlier or get clogged and also can cause Catalytic Converter damage. Naturaly aspirated motors run best on the lowest octane possible, where forced induction engines need higher octane to control the way the fuel burns due to the higher compression and higher heat conditions.

 

But in the manuel it calls for 94 octane,it is a high out engine(2.4 that is)

 

the 2.4 requires 94?!?!?!?

Th SS/SC only require 87! but reccomends 91!

Once your stageed though it REQUIRES 91

hell, a lot of states cant even get 94!! all of canada can't (iirc)! I have a REALLY ahrd time beilieving the 2.4 manual says to use 94 octane

 

it recommends 91 or higher, but says you can use regular 87... basically you want to use the lowest octane that won't produce engine knock... anything more than that is wasting your money

 

Thanks for the clarrification

 

The compression ratio on the 2.4L engine is 10.4:1. I would say that you would probably get best results with 89 octane, 91 would probably be ok as well. No need to go any higher then 91 though. I would guess that you would notice the best performance at 89 octane.

I didn't realize the compression ratio was that high on those 2.4L motors.

 

The manual says 91+ is reccommended but not required.

(edit: i think it is 91+, sorry)

 

Confused

 

manual says 91+ recommended but not required. I've put 93 from the start, and now even more since after the tune, no problems here.

First oil change was mobil 1 synthetic, i used castrol syntec aswell on my old car and never had a problem.

 

Canada gets 94!
they sell it at Sunoco

 

You won't notice a big difference between the two oils with daily driving but you will notice it in the long run your car will run smoother longer with less wear.
I think it is great that the SS/SC comes with Mobil 1 but it really is overkill.
Gm could have used a cheaper oil and accomplished the samething but by putting Mobil 1 in it from the factory people automaticaly assume the car is a performance car.
And you know Mobil 1 bid on the contract for more notariaty hoping to get into the younger crowd.(whom by most of my reading really like Royal Purple I have no opinion I've never used it.)
Mobil is good enough to be in Aston Martins, Vipers, Z06's and just about every other supercar so it is good enough for the Cobalt.

 

I did my first oil change with Mobile 1 synthetic as well and have always used Sunoco 94. It will not hurt the 2.4L. The higher the octane you use the hotter it burns and the cleaner it burns.

 

If you do use 87 octane on the 2.4. Chances are your motor will start to knock and that's very very bad for a motor.

 

I use high test, the book calls for it.