Originally Posted by The Critic
Originally Posted by Puckrobber
I thought it would be, too. But, I've taken this Jetta to the dealer for oil changes since I purchased it. When I checked the invoice at the first change, it had Castrol 5-30 put in it. When I inquired about it, the service manager said 5-30 was just fine for the climate I live in, and the difference from 5-40 was negligible. They only put 5-40 in if the customer asks for it. It's had both 5-40 and 5-30 in it, with no difference in engine noise or driving ability.
They were most likely using Castrol Edge Professional OE 5W-30, which is a 502.00 approved oil:
https://msdspds.castrol.com/bpglis/FusionPDS.nsf/Files/711A4665F31054FE80257F8E006CA9C9/$File/BPXE-A9VF45.pdf
There are many different varies of 5W-30 oils; they can be extremely different.
Ah, thank you for the info. My sister has the Jetta, currently. She took it to her mechanic friend who did the work.