Should I go with the manufacturer recommended 5w20 for my 1999 Honda Accord V6? Synthetic?

Question

It has 146,000 miles. I have no knowledge on engine oil weights or whatever.

I was wondering what kind of oil I should buy for it whether it be 5w20 or something else.

I was thinking on buying synthetic. Is there a problem with that? I've heard stories about synthetic oils. The previous owner only used conventional. The car has no noticeable oil leaks.

What's the difference between 5w20 and 5w30?

Answer 1

If it says 5w20 in the manual then i don't see a prob. with that ...difference between 5w20 and 5w30 is 30 is a thicker oil ... synthetic is fine to run some people say that it causes leaks in a car that is old because it flows better and therefore might find its way out of a old car not sure of how true this is  

Answer 2

Do you want it to last a longer time?  Use 5w-30, at least in the summer, especially if you do highway driving, or a lot of stop and go driving in traffic.  Every car in North America with a 5w-20 recommendation uses 5w-30 when it is sold in Britain.  The dealers don't even stock 5w-20 there, and will laugh if you tell them you need it.

If the engine is in fine shape, there is no reason you cannot use a synthetic or synthetic blend 5w-30 oil.  i have used a synthetic blend every winter for years, and find, in the summer, I actually use a little more oil if I happen to put in dino oil instead of the blend.

However, if there are any minor seal leaks, they could be pluged with a bit of dino sludge, and the synthetic could flush that out, creating a new leak.

5w-30 is a little thicker at the hottest temperatures, and has better reistance to high heat breakdown.  Both grades will perform well in winter.