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!
Question about oil...
-
kouki_monstor
- Posts: 165
- Joined: Sat Oct 08, 2005 12:22 am
- Car: '92 180sx
If there was syn in the engine before, it adds a grey area. I've been told many times that once you've gone synthetic, you can't go back. I've spoken with a Mobil rep and they said that mobil 1 can be mixed safely with other oils. So there's that grey area I was talking about. A simple flush won't do it, as there is still quite a bit of old oil that remains in the engine after an oil change.
My recommendation though if you're set on using that valvoline conventional oil is to make it a gradual change to conventional oils. Find an oil that's compatible with other oil types and use that for an oil change or two to try to dilute the synthetic (if there was) and get it out that way. Assuming a full synthetic was used, you could try going from mobil 1 and work it back down to the conventional stuff as the rep said that mobil 1 was compatabile with the other types of oil but didn't recommend it as it'd dilute the performance of the mobil 1.
My recommendation though if you're set on using that valvoline conventional oil is to make it a gradual change to conventional oils. Find an oil that's compatible with other oil types and use that for an oil change or two to try to dilute the synthetic (if there was) and get it out that way. Assuming a full synthetic was used, you could try going from mobil 1 and work it back down to the conventional stuff as the rep said that mobil 1 was compatabile with the other types of oil but didn't recommend it as it'd dilute the performance of the mobil 1.
-
ddgsxr504
- Posts: 6024
- Joined: Sat Jan 08, 2005 5:50 pm
- Car: 1995 Nissan 240SX SE 2007 Infinit M35 Sport 2011 Nissan Pathfinder Silver Edition
- Location: The real SoCal
Re: Question about oil... (kouki_monstor)
To start off, Synthetic oil is better anyway. As for swapping oil weights it's not necessary for you in Nevada since the temperature isn't drastic enough either hot or cold to warrant it. Given where you are I would suggest the 10W-40. I personally run Valvoline Syntec 5W-40 and have been ever since the car was bought in 1999 and I also have 162,000+ on my engine. If you are bent on going to conventional oil then I would say flush it and then gradually step it down over the period of about 3 oil changes.