Could I safely put synthetic oil in my car without it getting leaks? It has around 74K on it, don't know for sure, new gears were added and the previous owner drove around for awhile without the speedo programmed.

 

assuming all your seals are good, the synthetic will not create any new leaks.

 

yes

 

I'm currently using 5w30, should I switch if I change over to synthetic, or should 5w30 still work?

 

stay with 5w30

 

Just go for it

 

use 10-30

 

why, thinner is better

 

Thinner is not always better, use the 5w30 because thats what the car calls for. If you burn oil then you should use 10w30 same with if you have any leaks.

 

i use 5W50 Castrol syntithic (sp?) in my car, no problems, runs better than when I had 10W30 in there.

 

where is it exactly leaking from? (ie head) or just of the pan or something?

I wonder if i'm leaking, but in the morning i see no oil spots

 

i've got 190,000 miles on an LT1 and i use royal purple 5-30. no leaks, doesn't burn any oil, and i drive it like i stole it.

 

Sounds kinda like the famous rear intake leak. Dunno usually cars do not seal there own oil leaks.

 

Its possible if the leak is small enough, the oil impurities could plug it up, with synthetic it would be very odd since it has less impuritues in it.

 

Hey Blake.....I believe in the old saying..."if its not broken, don't fix it." Why do you want to switch to synthetic at 75k and risk a leak when you car is fine now? Just because its the in thing to do? As long as you change your oil ever 3k you'll be fine. JMHO

GOOD LUCK