I didn't think 18mpg was that bad... Listen to this one... Two tanks ago I got 276 miles w/ 2 gallons left (18.41mpg) and the last tank I got 255 miles w/ 5.5 gallons left (22.21)... That's after a race on the highway at 115mph

Oh lots of stop n go in the city... Any recomendations on oil?
that's just weird. crazy that you got better mpg after going that fast for who knows how long, than b4. i still think 18mpg is low… i think i average 21-22 city
Penzoil is the absolute WORST oil you can use. Use Castrol or Valvoline (although I have a bitter hatred for valvoline for personal reasons, not even their fault, just their factory rep is a thoughtless tool) I highly recommend Castrol.
I am sorry, I don't care what anyone says, 3000 mile changes on conventional oil, 5000 on Synthetic. I am sure your motor might be fine but the filter will lose its ability to filter the particulates. Especially with the detergent in todays oils. 6500 is too much. I don't even care that the Royal Purple guy told me I could go 10,000 between oil changes I am still going to do it at 5000.
The reason Pennzoil is so bad is because it is wax based and will gum up your motor. Not good. Also if you are going to switch to synthetic from standard motor oil, do it in stages, don't just switch directly over it can do damage. Run some Synthetic blend for a couple of oil changes then go full synthetic. Also be careful with sythetics as it will leak out more efficiently. Royal Purple has also been known to lubricate too well and I have heard of 4G63's spinning rod bearings after they switch from other brands.
good that you still recommend something u think is good even though you have personal hatred for it… a LOT of ppl won't do that.
i agree, i try to change my oil as close to 3000 as possible. something that works that hard for that long needs to be changed frequently, imo.
so if penzoil is like that, is that why i hear quaker state will gum your engine up as well?
i also recommend castrol. i use castrol gtx and the guy who changed my timing belt said the inside of my engine looked great for one with as many miles as mine has.