If i were to put this in my camaro, stock engine internals, lt4 cam kit, headers, etc... what would happen? since it's thicker oil would it have a harder time working it's way through everything?

 

I run it all the time Mobil 1 full synthetic no problems. I run this in the summer since it is a little thicker and since synthetics appear to be a little thinner than conventional oils. In th winter I run 10w-30

 

cool, cause I just put some in my car and I forgot to make sure I wasn't going to funk up my bearing clearances and all that jazz.

thanks

 

You might want to do a "search" on this.... there is no advantage to running a heavier oil than the engine needs. You are just wasting power pumping the heavier oil. If you are concerned about the Mobil 10W-30 or 5W-30 being to "thin" for summer temperatures, there is an alternative German-made Castrol synthetic 0W-30 synthetic that provides a little extra viscosity, without going overboard. Look for posts by "Patman".... he found it, has tested it, and has all the info.

 

I found Mobil 1 5w30 to be too thin. Although the diference would seem marginal, 10w30 was a lot better. After trying the 0w40 I got hooked on it, and was using it. 15w50 seems too thick, unless you have an old worn out motor.

 

really! huh, well i'll do some research on this tonight and most likely will go out and get me some in the near future, thanks guys. I don't know a lot about motor oil and how the viscosity affects things, but I knew one of you all would and you did.

thanks a bunch

 

At 300 degree oil temps, Mobil 1 5W-30 gives me less than 45 psi oil pressure at 6000 RPM, WOT.

I get 60 psi under the same conditions with 15W-50. I don't know how much, if any good that's doing my engine but it sure as hell makes me feel better.

Of course my application is a bit more extreme than most....

 

300 degrees is really hot. What kind of combo are you running to see those temps? Do you have a good oil cooler?

Rich Krause

 

Just a cam & headers. This is pretty normal, even for stock engines when run hard on a roadcourse.

I do have a good cooler but unfortunately it's still in a box on the shop floor. Just haven't had the time to install it yet.

 

I am an old road racer, so I am pretty familiar with the effect of road racing on an engine. 300 degrees is really the limit, it certainly shouldn't be hotter. You are giving up a lot of shear strength and viscosity at 300 degrees. I'd use the oil cooler, for sure. If you are going to run 300 degree oil temps, I'd change the oil VERY frequently and use something better than Mobil 1. I like Red Line, which you can get in 15W-50 and 20W-50 viscosity grades. Remember that if you are seeing oil temps of 300 degrees that the oil temp in the region of the upper rings and valve train is closer to 600 degrees.

Rich Krause

 

Oh, I know. I'll get that cooler installed just as soon as I can. Until recently I had only suspected the oil was getting that hot because of the loss of pressure and the fact that everybody else who doesn't have a cooler gets similar temps. Finally got the gauge installed and confirmed it.

My last oil had a whole 855 miles on it when changed (70 track miles). This batch will only have about 300 (120 track). This gets expensive. I think the cooler will pay for itself....

 

Now I'm sure it will. Finally installed it: http://www.jonaadland.com/Z28/Mods/O...lerMounted.JPG

Oil temps stayed below 275 measured before the cooler, 240 after at my last track day. The oil isn't burned black this time! I'm now using Redline 5W-30 and will run it for multiple events.

Back to the subject of general street use...I didn't like the M1 15W-50. I think it's just too thick (unless you heat it up like I was on the track--which you never will on the street). My valvetrain would make tons of noise until I had driven the car for quite some time. Not good--especially for short trips.

 

We run a GM Performance Parts crate motor in our late model stock car. The engine brand new calls for Mobil 1 15w50.

Aaron

 

Well maybe it's bearing clearances are setup for that , the LT1's are not at least not from GM. If you are convinced M1 is the ultimate oil just switch to 0w-40 or 5w-40 truck and SUV, either is better for the LT1 than the 5 and 10w-30 and both are suitable for yearround use.

 

I agree!! Me too..