Question about oil ...

[kouki_monstor]

I just purchased a ka24de which Im about to swap in soon. But the problem is, the previous owner doesnt know what kind of engine oil was previously used in the engine. The engine has about 160xxx miles on it. Im planning on using 10w-40 for the summer and 5w-30 for the winter, Valvoline non-synthetic. My question is, would a simple engine flush be all that i need to safely switch to non-synthetic, assuming that there was synthetic previously used in the engine... just to be on the safe side? If it previously used non-synthetic then its out of the question... im just trying to be on the safe side here...

Another thing, is it safe to switch from 10w-40 to 5w-30 in different seasons? As long as it's the same brand? Or is it the other way around? Diffferent brand but same weight and winter? Because if it's not safe to frequently change the oil weights then I'll just stick with 10w-40, since the engine has high mileage. Any suggestions would greatly help. Thanks!

[lazyfcker]

i heard you can use sea-foam to flush the motor and it will be fine to change to motor oil. and being it has high miliage, i doubt synthetic was in it.

as for the changing motor oils seasonly i have no idea, but sea-foam once again could probably solve that one.

[SX APPEAL]

Switching oil weights and/or brands shouldnt have any adverse effects, assuming your not switching from synthetic to conventional. Just dont mix different weights/brands in the engine at the same time.

[benemorius]

The switch is no problem, but why not use synthetic? Unless you ride around at 5k rpm all day, I'd stay away from 10w-40, too. 5w-30 is fine all season for most people.

[kouki_monstor]

well i live in vegas and the summers get considerably hott, so i thought a heavier weight and winter might help?

and yes, i do ride around at 5k rpm occasionally, because i take my car to the track alot of times, so i just wana make sure all the inernals are well lubricated. do you reccomend 10w-40 for track use?

[benemorius]

In that case, yes you might consider a heavier oil for track use, but hot weather is no justification for it. Your oil isn't going to be hotter just because the ambient temperature is, against popular belief. It may be a hassle to change your oil every time you go to the track, though.

[kouki_monstor]

thanks!