Garage mixed 5w-30 into my 5w-40. Should I do an immediate oil change?

[Oliver Smith]

Sent my 2005 350z in for a clutch and flywheel today, everything has gone fine but noticed they had topped up my oil. I phoned them to ask what grade and they said 5w-30, being a muppet I just said cheers and then started pricing up a service kit for this evening.

 

I have spoken to a mate who is a mechanic, he says mixing 5w-40 and 5w-30 won’t cause me any issues. Even if I push my Zed every now and then.

 

Just thought I’d put a post out there to ask advice from a group of people who all specifically know about 350Z’s. I know 2005 VQ35DE REVUP engines have a reputation to burn oil due to their not so great piston rings, that’s why I made the change to 5w-40 in the first place. But would like to know a bit more information before I make the decision to service it or not. Cheers!

[Coz@TORQEN]

Meh, as your friend said, I highly doubt you'll have any issues at all.

 

That being said though, for the sake of a bottle of oil which is what, £60? You might as well change it for peace of mind.

 

Otherwise, you'll wake up sweating at 4am thinking about the 'what if's' 

 

 

[Oliver Smith]

If I had the money I would just be doing the service, only issue is I have £70 to my name at the moment. Would rather that than £10 😭

[Coz@TORQEN]

Ah, that is a bit of a tricky one then, how much did they add? Are we talking 100ml or more than 1L? 

[Oliver Smith]

Not that much, I had serviced it relatively recently so they couldn't have added more than a couple hundred ml.

[ShortPaul]

I would not be to concerned mate 

[Ekona]

Wouldn’t even give it a second thought. 

[ZMANALEX]

Absolutely no drama, it will be fine.

[Stewal]

When you drain the oil you never get it all out: so when you first swapped to w40 grade you already mixed it a little bit with whatever was in there before.......no issues.

[Oliver Smith]

Cool I won’t worry about it then, thanks for everyone’s responses.