Just went to a local mechanic to change engine oil (E320). The mechanic put in 5W20. Later I found out that 5W40 is recommended for my car but the mechanic said it should not make any difference and I should be fine. Is this correct? No damage whatsoever to the engine? Thanks.

 

dont worry about it. just put 5-40 in at next oil change

 

It's the lower of the two numbers which is probably more important since you will get valve and lifter noise if oil is not thin enough. So, you are Okay until next time.

 

Thank you all for your comments. I really appreciate it!