Well just a quick question....

Would there be an issue if I ran synthetic oil after always running conventional whice uses a blend of both 223000 miles on the truck now.

Was always told by toyota it was synthetic oil used but all ways changes oil every 5000 miles for all the driving I used to do.

Always heard it was better not to change to synthetic after you always ran conventional oil. What are some of your thoughts.

 

I cannot say anything about the Tundra but my LandCruiser always had conventional oil I was told from the guy I bought it from. It had 160,000+ miles on it and had some oil leaks. I fixed all the oil leaks and cleaned up the motor and it looked brand new. I then had a brain fart to use Syn Oil (Amsoil since I was a distributor at the time) and after 2 days I seen oil on my garage floor. WTF!!! After looking closer it was the rear seal and after talking to friends I was told to try to go back to conventional. When I did I no longer had any oil leaks for years after this.

FWIW

 

Well I'm wondering if I had the same thing because I have always been under the impression. I was running synthetic oil and I ran the last 2 oil changes with synthetic because toyota was to booked up. Still maintained 5000 mile oil changes.

 

Thank you for some input.

 

Toyota recommends Mobil 1 full synthetic. I definitely wouldn't keep switching out every other oil change but if you start with Synthetic then stay with synthetic. Your oil is only as good as your filter so invest in the OEM filter or one with the same or better specs like Wix. Full synthetic never really loses its viscosity so you can go more miles between changes

 

That's is my issue toyota has done all my oil changes but they used conventional and I was told it was synthetic oil that was used but that was not true.

 

I will stick with conventional since I know the facts now thank you all for the replies

 

What makes you say conventional oil was used? You’ve been getting 0W20, right?

 

I was thinking the same thing as @landphil . Have you been running 0W-20? If so, then you've been running synthetic all along as there is no conventional 0W-20.

 

Don’t accuse me of thinking.

 

So I called to dealership where I bought my toyota and where my services were being done in the early life of my truck.
Since I requested them to change my oil every 5000 miles they went and changed my oil from synthetic 0-20 weight to conventional 5-20 per my 5000 mile request. But never informed me that the change was done at any point. Not a huge deal but it could of been. i have always been under the impression it was synthetic. This all got brought up when I called to my make an appointment for a oil change today.. Thank for the advice and help.

 

Was told that until the records were pulled 5-20 was being used.