I have a 99 Accord V6 with 150K miles. The leak is not too big. I plan on replacing all the seals on the motor except, obviously, the one that goes to the transmission. If I do this and eliminate the leak, can I safely put synthetic oil in the car?

 

Of course you can. Just follow the Manufacturers recommended viscosities.

P

 

i've always switched back and forth and never had problems.i got two accords,but i like synthetic.use 10-30 honda recommends 5-30 but i always use 10-30 due to the fact that i have over 100,xxx miles on my car's.

 

Could I get a couple of more opinions?

 

I heard synthetic on older engines can be bad due to the size of the synthetic oil molecules. Since you are replacing all the seals, I think you should be ok.

I've switched to synthetic at 100k on my F22B1, and so far no leaks from the seals. All good.