oil type? help!
 

I was wondering if anyone can give me a definitive answer about the kind of oil to use. I live in Chicago and it just snowed today, when it gets cold out my car starts fine but you can tell its running really rough (car vibrating and such). I run the car about 60 miles a day and it just seems like it never really warms up to smooth riding the entire time. I had 10w-30 full synthetic in there in the summer and just got an oil change today. I was going to put in 5w-30 full synthetic like I did last winter but after they drained my oil they told me they were out of it. They put 5w-40 in there for me.

How is this in comparison to 5w-30? I know that 5w flows better than 10w when its cold out and 40 flows less than 30 when warm but I think I am looking for a less visocisity all around since it's cold out--or will this not matter? It has 144k on it and i felt like the cold driving w/ 10w-30 was killing it..but theorhetically higher temperatures with 5w-40 would actually provide less flow less the 10w-30. I need some good advice on how the cold driving will be affected by the 5w-40. I have no problem changing the oil out to 5w-30 if anyone here is certain that it will provide for a smoother ride all around and that the 5w-40 will somehow adversely affect driving.

Also, I just noticed that some companies offer 0W oils. Would a 0W-30or40 be even better?

Any help is greatly appreciated.

Welcome to the forum. The first rule of posting is to tell us what car you have.

i use dello 400 in my 88 300se .. but im curious if i can use valvoline racing oil sae 50 or 60 .. have some free cases laying around but not sure if its ok to use .. also have some full synthetic 10w-30 .. any help would be great ..

dello 400 seems to keep my engine super clean (guessing cause its diesel oil) .. only use it cause its free oil

Depends what car you have. I assume its a MB of some sort since you are here?

just when i thought i put down all info

99 c230 kompressor

Look up your car here, for M-B approved oils:
http://www.whnet.com/4x4/oil.html
Personally, I would go for Mobil 1, 0 W 40, and use it year-round. ;)

Delo 400 consistently gives the best UOA and therefore I rate this oil among the best and certainly the best in terms of value.

If during your 60-mile day the car never smooths out, I'd say it's time to look for problems other than oil on your car. On a cold morning, a healthy engine with a reasonable oil grade should stumble for no more than 5-15 seconds on startup. Your car seems to have a driveability issue. Going from 5W- to 0W- won't solve this issue. How is the tune of the car?

especially if the value is free :D .. thanks for the response

by tune u mean..

what does a tune up consist of anyway?

i should also mention that in the summer the car drives like a dream....my mechanic said it idled so smooth he thought it died at stoplights

You didnt state it was running poorly.

Has your mech examined the motor and trans mounts?

It's 8 years old. Rubber doesnt last forever and also transmits more vibration at colder temps.

When was the last time a service was done?
Have you ever changed the:
Plugs?
Air filter?
Fuel filter?
Coolant?
Brake fluid?
Trans fluid?

If you don't know time to make an appointment with your friendly local MB dealer.

That's true, didnt think of that. However, the acceleration is rough and there is a definite loss of power. I don't know how else to explain it..it just feels like its running cold.

yes, yes, yes, yes, yes, no.