Oil change intervals

[Z31toZ32]

I've got 145k on the clock and recenty switched to synthetic, mainly due to me switching weights in my z, I had a bunch my old weight leftover. Now that I'm on the good juice, can I safely lengthen my interval from 3k to 5k or more? I'm on mobil 10w30. Thanks.

[OwnerCS]

M1 at 5,000 should be fine. I believe if you were changing oil at 3,000 miles, you have been maintaining other important items with the same care level. Other important factors to consider though:

1) Oil filter quality
2) Time interval (in months) between changes
3) Short haul city vs.highway driving

[loystock]

I use 30-weight Mobil 1 Syn in all the cars, except 03Q where I put 40-weight to avoid oil consumption issue. I used to do 4/4 (4-mo/4,000 miles) but switched to 6/6 (6-mo/6,000 miles) last year after oil analysis from Blackstone for the 97 I30 and 03 Q45 came out good. So if you want to extend your OCI, have and oil analysis from Blackstone, @ $25.

http://www.blackstone-labs.com/free-test-kits.php

[NutriaforBreakfast]

like synthetic and I take it to 6000 miles-have used the mobil turbo diesal 20w-50w here in
texas since it is so hot from March to October and use 10w30 during the "cooler" mo.
If an oil change place changes your oil remember they might strip out your oil plug and pan
(overtightening) so the longer you can go between changes the better
Just got back from St Thomas/St Johns. If youve ever been there those motors and brakes
go through h**l up and down those hills. Perfect place for a shop on oil changes and brakes maybe
Back to 108 degree today Never thought I would be jeolous of Houston weather!