Originally Posted by OilUzer
Originally Posted by CR94
Originally Posted by NH73
... The Toyota I have just says ILSAC GF-5 0w20. So basically I just need to use a 0w20 that meets ILSAC GF-5 or later. Most 0w20 is sold in full synthetic but there are a few synthetic blends out there. 0w20 will require better base stocks to make vs. 5w20 and that is probably why Toyota specs 0w20 with a 10k OCI.
My Toyota, likewise. They also say you may use a conventional 5W-20 if 0W-20 is unavailable, but must replace it at half the normal change interval. In some contexts, they omit the "conventional" adjective, in otherwise similar statements. What's conspicuously missing is clarification as to whether synthetic 5W-20 of the same (apparent) quality as a manufacturer's 0W-20 is equally OK for the same change interval. I'm betting it is, although I'm technically violating their prescription by using 5W-20.
Interesting!
My Toyota says sae 0wx20 must be used but if sae 0wx20 is not available, sae 5Wx20 maybe used. However it must be replaced with 0Wx20 at next oil interval. There is no mention of reducing the interval or using a synthetic 5Wx20. Since 5Wx20 can be syn-blend and sounds like you can even have a conventional 5Wx20 as well.
Besides there are many owner's manuals that don't mention anything about syn vs. dino.
Maybe 0Wx20 or d1g2 or some other specs (BMW, etc.) forces the use of synthetic but there are other cars that just recommend the grade and api spec and nothing else.
I think they should specify the oci as follow if they are recommending any grade that can be dino or synthetic:
- x miles with conventional
- x+2000 miles (for example) with synthetic
Owner Manual are what they are. My guess they don't do that is so not to add to confusion. No doubt a synthetic 5w20 will be just as good as a 0w20. Al that as long as extending OCI's can be done with UOA's.