OEM 5W-30..can I use 10-30 or 5-40 also?

[edwx]

I have an '03 xls w/145k and a very slight oil leak from the front seal. It's time for an oil change. I live in upstate NY (cold winters!) The OEM recommendation is 5W-30, which is what I've used up to this point. I think I've heard of people using these other oil weights (when the OEM is 5-30), but I'm not sure why. Do they switch to a heavier weight on older vehicles because they will make a slightly worn engine run better? Does a thicker oil leak less? Being able to use these other weights would give me more options. I'm sure if I spent a few hours on BITOG I could research this, but I just don't have the time right now. Any feedback will be greatly appreciated. Thanks!

 

[chriswells78]

Just use the 5-30. You'll never notice any less leakage from a heavier oil. You will notice worse gas mileage using a heavier oil.

BTW your leak will only get worse. Your front seal is a neoprene ring with a spring behind it. It will leak when the neoprene wears out and will only get worse. You should replace it.

 

[nascar_intimid]

good advice!!!!!