Patman, you run ow30 in your car even during the winter up there?

 

Does anyone run Royal Purple?

 

Ive got lil over 38k on the car now, what oil should i run. my friend told me to run the M1 0w40, but is it time for oh say 5w40?
-Ryan

 

Yep, I run this oil year round, it works awesome in the winter since it's a 0w oil, but in the summer it works awesome too since it's a thicker 30wt, and almost a 40wt actually.

 

Woody99,
I did run Royal Purple 5w-30w, it's supposedly gives more hp, but i don't know about this- did not see it at the Dyno. I did notice late Oct, when the temps here started to get below 35F, Piston Slap. I did not experience this last Feb or March- I buy the Z in late Feb, running Mobile 1.
I ran R.P. all summer long with no issues at all un til Oct... Before storing the car I switch over to Amsoil 10w-40w. I start the car once a month, I have not had ANY PISTON SLAP.

 

only 10w30 Royal Purple in my 98 formula since i bought it...no issues...and she pulls hard...very happy w/ results

 

Just because piston slap is quieted down, it dosnt mean that oil is necessarily better for your engine. Is it possible that the thicker viscosity is causing the cold pistons to rock in their bore because the piston is sticking to the side of the bore? My slap is much quieter when I use lighter weight oils like M1 5w30, but it burns off a half quart over 5-6K miles. With GC 0w30 my engine is protected better, and burns no noticeable oil at all at the price of some added piston slap and lifter noise. Ill deal with it.

 

There are numerous past threads on your question. There is no consensus and the answer the depends on weather, usage, race time, personal preference and many other factors. Use 10W30.

 

You should be fine with the 5w30 year round. You don't need to change viscosity in the summer.

 

Patman, not sure whether German Castrol is going to be available at Autozone in the US much longer (from another post). I've got enough stocked up to do another oil change, and I'm going to have an oil analysis done after that interval. But if I can't get more of that oil, I've got to know what to buy.

Mobil 1 0W40 is available everywhere, so that is what I am thinking of using. But would it be better to order Amsoil 0w30 online? I know that you have said both are good, but what would you go with? If I do switch, I'll get an oil analysis done of the other kind as well so I can compare.

 

There is a US made costrol 0w30 thats just starting to be made to the same specs as the german oil. It even has the same iridescent green glow to it. Look for all those good specs on the back. Look for a label without any yellow in it, and it might be the "Good" american castrol.

 

I'd probably go with M1 0w40 over Amsoil 0w30, simply due to cost. Amsoil 0w30 is very good, but very pricey too.

 

I used to run Mobil 10w-30 non synthetic. Then at 8500 miles I switched over to M1 10w-30. I thought I was getting M1 5w-30, but discoved it was M1 10w-30. Anyway, since the change to synthetic my gas mileage has increased 3MPG. Car doesn't feel any different and I still drive it the same as before the oil change. It still has the same piston slap.

For me the added cost of synthetic is off set by the increase in MPG. My next change will be to M1 5w-30.

 

What's the best oil filter?

 

Some prefer K&N, some like WIX/Napa Gold. I'm running the Napa Gold right now.

 

M1 0W-40 for my SS
M1 5W-40 for my Silverado

 

I like the K&N #2006 Truck Filter.

Bill

 

Saw this last night - good info on oil filters!!


https://ls1tech.com/forums/showthrea...l+filter+study
Todd