My '93 has 174Kmiles on it. I have been using regular conventional oil all these time w/o any oil leak problem. I change oil every 3,000 miles though.

 

Good enough for me. Thanks, guys (gals?)

 

IMO, Marvel at every third oil change and an annual flush are a good way to keep the engine clean, but then again, oil problems are rare if you change it regularly and with quality correct weight fluid.

 

I bought my accord with close to 150k and put Amsoil in at my first oil change. It did start an oil leak after a while and I have been told that synthetic will do that with higher mileage engines because with the conventional oil the gaskets swell or expand and the synthetic repairs it, but often loses their seal. Mine is in the oil pan and is relatively inexpensive to replace. Amsoil recomends changing every 25k or 12 months and they now have a 25k oil filter to go with it too. I don't drive that much, so I usually change mine about 10k to 12k.