switching to synthetic not sure if its safe ?

[johnathandm]

hello everybody My 4runner has 271K on it still running strong, and my question for you guys today is. is it safe to use a Semi Synthetic oil For the engine? Also Am i able to do it with the Trans And the Real Diff? Also its a 4x4. I Just want to Know what are my options? i did some research but i could not find anything specific that i was looking for Thank you.

 

[Elton H]

id just stick with regular oil

 

[Koz]

Do yourself a favor and stick with dino oil. With 271K miles you would be asking for trouble!

Koz

 

[MAD 69]

I was also wondering about this, my runner has 160K...

What do you guys think about synth ATF? Does anyone use any of the Nippon fluids such as Eneos? How about Rad coolant as wel, I ask because I have no idea what kind and brand the original owner used. The truck runs great and I would like to keep it that way.

 

[Koz]

You could also run into problems changing the trans fluid (slipping or shifting hard). No problem changing the anti-freeze. Use long life Toyota anti-freeze.

Koz

 

[Gerdo]

I switched everything but the engine to Synthetic at about 100k. I went to full synthetic in the engine at ~180k miles. I have had zero issues, I'm at 220k now.

Full synthetic will not damage old seals. It does flow better and does keep and engine cleaner so some people have leaks when they go to a full synthetic because it cleans the gunk off the seals and flows thru worn seals.

Change to synthetic and see what happens. If you start seeing more leaks then switch back. If you have kept up on oil changes then you probably don't have much gunk in your engine now.

When I went to synthetic in the trans, transfer and diffs I noticed an increase in gas mileage.

I went to synthetic engine oil so I could stretch oil change intervals.

Note: If you automatic transmission has a conventional oil in it I would stick to that unless you do a full trans flush. The 5 quart drain and fill would give you a 50/50 mix.

 

[IanB]

I switched everything but the engine to Synthetic at about 100k. I went to full synthetic in the engine at ~180k miles. I have had zero issues, I'm at 220k now.

Full synthetic will not damage old seals. It does flow better and does keep and engine cleaner so some people have leaks when they go to a full synthetic because it cleans the gunk off the seals and flows thru worn seals.

Change to synthetic and see what happens. If you start seeing more leaks then switch back. If you have kept up on oil changes then you probably don't have much gunk in your engine now.

When I went to synthetic in the trans, transfer and diffs I noticed an increase in gas mileage.

I went to synthetic engine oil so I could stretch oil change intervals.

Note: If you automatic transmission has a conventional oil in it I would stick to that unless you do a full trans flush. The 5 quart drain and fill would give you a 50/50 mix.

How much of an increase in mpg did you see with the change to synthetic fluids? Is there any reason you shouldn't blend dino and synthetic ATF, outside of reduced effectiveness of the synthetic?