Weight of oil ??
 

Okay I see in the owners manual it specs 5w-30 oil for the oil change. I took my HHR 2.4 into a shop to have the oil changed and they did not have 5w-30 so they put 10w-30 oil in it.

The manual specifies not use 10w-40 or 20w-50 but does not specifically mention 10w-30.

Will using 10w-30 oil cause any issues?

You are out of warranty, don't worry about it. But change it to the required oil next change.

But IMO, you need to use a shop that complies with your vehicles' requirements and knows what they are doing.

Also, the Owners Manual is only providing a description analogy for the type of oil not to use. Under your thought process, it would be OK to use 0w, 50w, 30w-50 and so on. GM/Chevrolet is specifically telling you to use 5w-30 because they designed the drive train around that perimeter, tested it under that perimeter, and offered it to the public under that perimeter.

OK, if the warranty is the only issue, then no great disaster, right? I mean its a 2006 with over 100k so I didnt think I had a warranty to begin with.

That being said, I was mainly worried about any mechanical issues or damage it could possibly cause.

I also talked with a friend who is an oil expert, and he told me that the first numbers refer to the viscosity of the oil, and that the only real difference between them would be during cold temperatures.

So based on the reply, and this information, its appears like I may be ok.

The shop told me they would go get some 5w oil and change it for me. But since its (the 10w) already in there, will it make a difference?

I think the answer lies in the fact the shop offered to change it back to 5-30. Have them change it asap.

Hey Whopper now you have to change your oil again, hope you own an oil tanker.

I'll add that to my list of reasons for, "Why I change my own oil.":lol:

Well, at the least they told you they put the wrong oil in there. Just think of how many customers aren't told these things.

lol what kind of shop doesnt have oil in stock? that seems soo sketchy to me

Especially since 5w-30 has to be the most common oil on the market. They must have had an unexpected blitz of oil changes. The only time I see oil out of stock is when synthetic is 25%+ off at an auto store.

The difference between 5w-30 and 10w-30 is about 5 degrees at the minus temperature where loss of oil flow is measured (-20 and -25) and since summer time is here the 30wt is the most important. It is usually measured at 200 degrees or so which is sort of the standard temp an engines internals are figured to run at. Since temps get down to 60 or so at night in the midwest I would say the difference between 5w and 10w will not matter. The car will be ready for another change by the time fall and cooler weather gets here and then go to the 5w-30 oil.

Relax, don't worry. Not a big deal in the short term. There probably are thousands of Ecotec cars owned by "old Schoolers" that refuse to believe that 5w-30 is a valid oil to use in any car. "I have used 20w-40 ever since I got my first Super88, and they had to do a lot of talking to get me not to use 40 weight like I used in dad's tractor."