Winter is coming and I have a few questions:

I took my 08 SI to the dealership and they filled it with 5W-20. I know the oil cap says 5W-30 and in the owner's manual it says use either.

They said that with winter coming its a good idea to use 5W-20. This is my first oil change in the car.

Are they right in putting -20 instead of the -30 that is on the oil cap on the engine?

 

Should be alright.

 

As Alex_G said, you'll be fine.

All modern oil that we put in our cars are multigrade. The two numbers represent the range of thickness of the oil. Usually the lower the number, the thinner and better suited for colder temperature. Some expert argue that in selecting oil, we should choose the multigrade that has the least gap (ie: using 5w-20 instead of 5w-30) to minimize variance but in all honesty, I've used both and never had any problems.

Good luck!

NOTE: I've used 5w-20 full synthetic for my past 2 oil changes.

 

Thanks for help. I thought I was in good shape. I just didnt know if the K20 engine needed that extra thickness or viscosity.