Ok i bought 5W-30 because thats what was recomended for my car by the dealer. Now my mechanic said because i got 95,000miles i should be using 10W-30 or even 10W-40. He said i shouldnt wait more than 1500miles before changing oil again sicne i used 5W-30.... what do you guys think???

 

I bought my 95 T/A with 86k miles and went straight to 10/30 Mobil 1 oil. I would personally recommend using 10/30 on anything over 75k miles.

That is just my 2 cents, but if you look for other oil threads here on this board, it seems that 10/30 Mobil 1 is the most commonly used oil.

 

I use 5w-30 and i have 94,000 on the car. I find it makes for easier starts.

 

Switch to a 40 wt oil now. Your engine will like it alot better. 5w30 IMO is too thin for a 350 with low miles. My suggestion is buy a bottle of auto-rx from www.auto-rx.com and do a treatment. Then switch to a good synthetic like Mobil 1 0w40 or perhaps their Delvac 1 brand (fleet oil) 5w40 if your Z doesn't burn any oil.

Jason

 

It depends on which 5w30 we're talking about here. If it's Mobil 1 5w30, then yes, it's probably too thin for your mileage, since their 5w30 is almost a 5w20. But a 5w30 like Redline or Amsoil, or one of the high mileage oils out there, would be closer to a high 30wt oil. If you're gonna use Mobil 1, go with their 0w40, or mix in a quart or two of 15w50 with their 10w30.

I would never use a conventional 5w30 ever though, it'll thin out far too quickly. Same goes for Royal Purple 5w30, it thins out incredibly fast (it went from 11.4cst down to 8.8cst-well into 20wt territory-in my wife's Honda in just 2600 miles)