BAD OIL? or GOOD OIL?

[nelapse]

Im using Mobil 1 fully synthetic 15W-50 think that would harm my engine? it doesnt run bad... but i wondering if that is a mistake... should i go lighter in weight?

 

[Chuckt]

im fairly sure the 420a is best running 10w30

 

[Urban_S]

Is it bad to run 5w-30 in my 420a? I got a case of the oil from my friend when he sold his STI he could not use the oil in his truck so he gave it to me.

 

[nelapse]

5w 30 is usually for newer engines with less miles

 

[Defiant]

From all the oil stories here and everywhere else, it really doesn't matter.

I'm of the belief that you're spending too much on oil if you're using synthetic. However, this belief got one of the guys at work to _give_ me five quarts of Redline, so that's in the '95 now.

It still runs the same as it does with the Wal*Mart jug oil. And the leak didn't get any worse with the synthetic.

The oils they're making these days are just too good to have to worry about.

 

[nelapse]

synthetic has better viscosity does it not?