I have a 1999 Dodge stratus. Its got 185k on it and runs good. What oil weight would you recommend? How about converting to synthetic blend? also when i start the car, it likes to jump up to 1800 rpms for a second or 2 then goes back down. Is that normal for these cars?

How many mpg does the 4cyl engine get? thanks

 

I would use whatever weight is listed for that engine. Synthetic blend is OK to switch to, but going with a lighter weight may result in more oil consumption/burning, or even leaking. It's pretty normal for most cars to jump up in rpm's for a second or two before regulating itself. When it's cold out, it's normal to stay at a higher rpm until the engine warms up.
Not sure what the 4cyl (do you have the 2.0 or the 2.4?) gets, but the 2.5v6 gets me about 24mpg highway.

 

I put 10w 30 in it, which from what i heard is what these take. Also the RPM thing happens hot or cold, all the time. i could understand how it would do it while cold but not warm. Lol.