Thicker oil on high mileage?

[aleosa]

Its coming up to oil change time and I have been hearing from various sources that it can be advisable to change the oil a grade thicker as the engine gets more miles on it. So far my SR20DE naturally aspirated has 121000 on the clock and the car runs very well. It is totally stock spec. It has been on Mobil1 or Castrol Syntec 0W30 or 5W30 for all of its life changed every 5000 miles religiously with OEM filters. It burns no oil and has no oil leaks. It is driven fairly conservatively but revved high and wide open throttle on the highway at least a few times a week. It is driven 80% highway and for long periods.

I have been told that the clearances on the bearings get slightly bigger as the engine wears and a thicker oil might offer better protection... is this really the case and when should I think about going a grade higher? say 5W40? My main aim is not so much performance but to maximise the engine life. I hope to get at least 200k to 250k from the car.... any advice appreciated!

[LilAznFishinDude]

You'll be fine going your current oil grade and rate of change I wouldn't worry about oil viscosity for another 30k miles. But then again, that's just me.

[Grimsta]

At 120,000 switch to 10w40. At 250,000 go to 25w50. Thats the procedure I follow with customer cars. You'll be good with the 5w40 though. I use Eneos 5w40 in my P11 w/ 160,000

[SuperblkStalion]

well on my old b13 i was like 3k miles away from hitting 300k on the original motor and i always used mobil1 5w-30 so there you go. had i not crashed it who knows how longer it would have gone.

[Jakeeybaby]

ams oil

[diptenkrom]

i would keep up wiht what you are doing, it has not caused any problems and sounds like you are on top of things.