Does it matter what weight oil we put in our cars.
10w 30
10w 40
etc..
someone just scared me saying I will blow mycar up for using 10w 30. I think hes full of s***t though.

oTher than the temps outside?

 

Not that big a deal. I use 20w50 in the summer, and 10w30 in the winter. Mazda recommended 10w30 for all year use. So, no, your car will not blow up.

 

I have a little 12a engine, and i run 10w30 winter, 20w50 summer, and its still going... 130k miles and driven hard

 

that's what I use....except that Okinawa doesn't have a winter

 

Mobil 1 15w-50 full synthetic, baby!

 

Castrol 20W50 year around in Cali. 74K on original motor and still pulling strong.

 

Thats what I thought but he is swearing to me that if you use anything other than 10w 30 your engine is gonna be history. I just wanted to triple check and ask you guys.

 

Who is he?

ALOT of 7 owner's use 20 W 50...can all of us be misled

 

Just don't run your engine ~2 qrt low the first two days you have your car.

 

I used 20w50 all year last year, but this winter, it's getting the 10w30

 

also the synthetic camp seems to be pretty strong these days. using 20w50 dino now, thinking about 15w50 synthetic mobil 1 like jonski for next change. that should do for the winter too.

 

I was using 20W50 dino when I blew an apex seal last Christmas eve. (merry Christmas!) now, I'm scared to stick that shtuff back in. I was worried that maybe the oil injection system shooting in 20W50 upped the compression in the combustion chamber a little too much (vs. 10w30) and I kissed my seal bye bye. Does oil weight effect compression through the oil injection system? I would think a more dense oil would not compress as well.