A couple of weeks back, my car was at the shop getting my gears changed, and they said they would do an oil change for free, so i figured why not (i normally change my oil). The felt great, but lately it feels a littel werid, it might just be in my head. My question is, if the mechanics didn't drain the oil out of both places, and then they filled it up w/ 5 qts, would this really hurt performance, and would it be displayed by a higher oil temperature reading on my guage? I pulled my dipstick out, and the oil level was alot higher than full, but real scarce, and very thick down by full, but the thickness came up a little. I'm really hoping the mechanics didn't overfill it, and i will get it checked tomorrow. But would an overfill of oil, be related to a higher oil pressure reading on my guage? Thanks.