supermegaglossy

ok.. i switched to synthetic oil my last change (about 3600 miles ago) and obviously, no matter what, you should change your oil as often as possible, but on synthetic you're supposed to be able to go longer, am i right? well... my oil is really dirty. i remember checking it at about 2800-2900 miles into it, and it wasn't NEARLY as dirty. is the dirt factor exponential? seriously...lol...

but i'm thinking that there might be an underlying factor here..

i am also getting really bad gas mileage. I had an O2 sensor in my exhaust replaced (thankfully under warranty) and then i went on a 1000 mile trip that weekend (also on this same oil) and i got great mileage. 300 miles to a tank. this a was about 1.5 months ago.

i mean, where i live now has a lot of hills, but to go from 20-23 mpg back home (and even more on the hwy, obviously) to like less than 15 mpg seems a bit obsurd. i could understnad 18-19, but below 15 makes me wonder if there is something wrong...

help! advice! thanks guys

oh also, i've got about 60k miles.

fizzle

First of all, Yes you should be able to go longer between oil changes with synthetic (some people dont however). Also my guess on the dirtyness of the oil, is since you just switched to synthetic it is cleaning out some of the smaller areas of the engine as well as maybe a little old oil left in the motor. I may be talking out my ass, but I have been told synthetic will find leaks when they would be hidden with dino oil. I would change it and watch the next batch of oil for cleanliness. Of course this could all also have to do with some other problem you may have - which unfortunatly I cannot help with

DanMan1464

i used to get 16 MPG with no problems....

supermegaglossy

good point, i never thought about that, and it was my first time using synthetic.