Hi, i have a 93 leg auto with 278,000km. I like in Canada and was wondering for my next oil change if synthetic oil is better. I heard something about the seals at the beginning leak. But what i really want to know is which one so i need for summer,winter, and how often i need to change my oil.Thanks

Change the oil every 6-7k miles or six months.

 

I am a big synth fan, but at your mileage I would stick with a 10W-40 mineral oil. Unless you like removing the engine to replace the rear main oil seal? It's quite likely to start leaking. Along with rocker cover gaskets and camshaft seals.

 

During winter a 5W-40 might do well, too. Might need to go for semi-synthetic for that kind of cold flow.

 

If you get a good oil change interval going, a 20W-50 oil could pay off during summer.

I put in mobil 10w30 which leaked on me during the winter. since then I switched out with normal oil 10w30 and it luckily stopped the leaks. Anyways if your car doesn't leak with synth i would go for it other wise I wouldn't worry about it, normal oil does its job doesn't it? if the synth doesn't leak i have heard people keeping it in their car for over 10,000 miles.

btw i have a 93 legacy with about 160k miles.

but if i go with syth can i go back to 5w-30?

Sure, no harm no foul. Syn is probably a wasted expense for you though as the only way to normally recover the expense is with extended drain intervals. Odds are you would add so much oil between long changes it would not pay.