Will a small difference in oil viscosity ruin my car?

I have an '07 Kia Spectra5 and was told that if I don't use the proper oil for my car my warranty might void. I just found out that the place I have been taking my car has been using 5W-30 and my car says it should be 5W-20. Is there much of a difference? Will it mess up my car? I know absolutely nothing about cars so go easy. heheWill a small difference in oil viscosity ruin my car?
No problem in the summer. Make sure you go with 5W-20 in the winter. Higher viscosity is the sort of substitution they are warning against.





Apparently the major changes that brought us engines that last several hundred miles included closer tolerance in oiled bearings. Higher viscosity oils hold idle oil pressure better but actually lubricate less well because the critical matter is oil delivery. I guess that back when an engine was spent at 100K miles that didn't matter.Will a small difference in oil viscosity ruin my car?
It's fine, just use the right oil next time you change it and if you have your car warrantied, don't tell them what oil you use. Tell them you use 5w20. They don't know, I promise. If you tell them, that just gives them another excuse not to honor your warranty and they have MANY. Their goal is to charge for as many repairs as possible because the manufacturer doesn't pay the dealership nearly as much as they'd charge you to fix your problem.
no it will be perfectly fine. all it means is when the car is at the propper temp the oil will be a little thicker, but thats all. I actually use 20W-50 because i like having a slightly higher oil pressure
Don't worry you didn't cause any damage. You might lose just a little bit of gas mileage because of the thicker oil but otherwise your fine. Just switch it back to 5W-20 at your next oil change.
For a long time 5W20 was specified for some cars but it was not available in the US. Most used 5W30 without trouble. However, today there is no excuse. It is readily available.
5W-30W will not hurt the engine.Next oil change if you are concerned make sure you ask for the 5W20W.
no a heavier woeght oil wont hurt it,honestly i would stick with the 5-30 but fopr warranty reasons next time just make sure you tell them 5 20
dont worry/when you change oil next time tell them to use the lighter oil/