Ok guys... I know GM recommends the 5w30. But awhile back prior to my engine build I had switched to 10w30 as per recommendation on here (I was still stock at the time).

I'm due for an oil change and was curious what you guys think? Now that I'm no longer stock and have a higher performing engine. What's gonna be the difference between the two?

I'm a die hard Mobil 1 guy.... so no changing my mind there. But I was also thinking of putting a treatment of Slick 50 in it as well. Been a pretty big believer of that stuff.

This car will be driven mostly in the southern california area... with the occasional trip to phoenix, az...

I drive it maybe once a week... usually putt around, but absolutely romp into it every once in a while. It's a street car so I drive it like one

thoughts?

 

I would look into the Valvoline VR1 race oils honestly. More zinc and phosphorus = more lubrication. M1 is good stuff, but the VR1 gets my vote. 10w30 is just slightly thicker, not gonna hurt anything to chance. Try it one oil change and see how you like it.

 

In hot weater 10-30 is fine. I personally run GC 0-30 in 90*+ but it also getS> 30* here often in winter. The VR1 oils are great especially with older stuff but with a roller cam they are not necessary IMO... If I tracked my car incessantly in hot weater I would consider a 20-50 oil.... a lot depends on how your car is used... mine is a streetcar that likes to pick on ustangs and the ocassinal ricer lol...

 

Remember, the 1st number in the oil rating is for cold temps, so both the 5w30 and 10w30 should have the same viscosity (30) when the engine is warmed up. Personally I run 10w30 in the summer and 5w30 in the winter.

Here's what the 2001 user manual says exactly:

 

That's exactly what I do...

 

i run 20-50w purple stuff i live where its 120+ every day 29 palms

 

German Castrol 0W-30 is a higher viscosity oil (at 100 degrees C) and would be a good oil in the stock bottom end. I don't use Mobil-1 any more, too thin at temperature and I don't like the brown varnish it leaves on the motor internals.

 

Same here.

 

10w30 if you don't live in places that get 20 degrees and lower or just for the summer time, and switch back to 5w30 during the fall.

 

i run valvoline VR1 20-50w all the time in my Z.

 

0w-30 Castrol....here..been in my 408 since after break in...30k now 60psi at idle...

 

I run 10w-40 in summer, 5w-30 in winter. Will probably go to 0w-30 for winter if I still live in Maine, I try to start it and move it around a little a few times a month on warm days and get it up to temperature.

 

Mobil 1 is a fairly good choice.
Don't waste your time or money with Slick 50...it "MAY" have been of some value with conventional oil but Synthetic is "WAY" better than conventional.

My personal choice is Amsoil. No other oil has one-tenth of the data available that they have to back-up how good there oil is.

 

German Castrol or Amsoil.

5w30 or 0w30 unless you're in a very warm climate.

 

I just put that in my motor yesterday. I'm taking it out just too heavy for me I am seeing 75PSI cruising down the highway dare I lay in it a bit she climbs hard. I just ordered the VR1 in 10/30 from my local NAPA I like all that I have read on the VR1 and will run it for awhile before I go to synthetic.

 

Winter= 5w/30w
Summer= 10w/30w

 

i currently run 10w 40 in mine.

 

good info guys... gonna stick with the 10w30 then. It's what I'm putting in my mustang as well so I went and bought 3 five quart jugs today. So they will both be getting oil changes tomorrow

that damn mustang takes 7.5 quarts! and it's a V6!!!! lol

wtf...

 

gm recommends a 5w30 but 10w30 is fine, has better shear resistance. also guy running 40 and 50 weight all this is doing is increaseing your oil temps and lubercating less, thats why gm recommends a 30 weight oil for the bearng clearances. i run amsoil 0w30 sso. who cares about the first number really that is the weight at 0 degrees. so in cold climates it is important,

 

Ouch to thick for start up.