Zeal3

iTrader: (1)

I usually use 10W30 non synthetic when i change my oil bcs of high mileage. (the engine oil cap says 5W30)
If i go synthetic should i use the 5W30 or 10W30?

JimsGX

I've read that the synthetic maintains its rated viscosity better than dyno oil does with variations in temperature. I'd stick with the recommended 5W30 unless your burning oil.

JAndersson

I use Mobil 1 0w-40 and it works great. But then I live in cold Sweden and not in sunny California so a 5w-30 fully synthetic oil should work better for you.

j three

I just changed my oil three weeks ago and I used a different combination and the car seems much peppier. I got five quarts Lucas synthetic 5-w30 one lucas synthetic oil treatment and one zmax. put the aditives first then ad oil. You will have some of the fifth quart left over, so just keep the left over to top off the oil untill you change it next time.
I have a 99 LS with 106k miles and it is noticeably smoother and slightly better gas mileage. I have quite the heavy foot so I can Definitely feel the added zip. Also I was barely getting 150 mi per half tank and I just got about 170-175 this past half tank.
My father got the same combo and he was telling me the same thing before I said anything about it to him. I would recommend this to anyone who has an oil change coming up soon.