Originally Posted By: awol350
I have a 07 Kia Specta Ex.. I have been running M1 5w20 synthetic OCI = 4k. Would it be safe to switch back to conventional at this point? I purchased Mobil Super 5000 5w20. Suggestions please
If your goal is to save money, switch to Toyota 0W-20 SN.
Dino oils don't maintain their fuel economy over the OCI because of oil degradation. On top of that, Toyota 0W-20 SN has a very high VI, which helps with the cold fuel economy. Not to mention the inherent friction benefits of the synthetic base oil.
In my actual experience, I switched from PYB 5W-20 SN (whic is loaded with moly) to Toyota 0W-20 SN. The difference was like day and night. I will never go back to dino. The engine runs a lot smoother and I am seeing fuel-economy improvements around 5%. That's going to save you a lot of money over the OCI. On top of that, you can have somewhat longer OCIs and you will still be fine.
See if you can get it for under $6 per quart where you live. You might try to negotiate with the dealer and perhaps get a whole case of twelve.