RPMs and overdrive questions
 

1999 Mercury Sable 6 cylinder
103,000 miles

my fiance recently acquired this car and the gas mileage has not been very good (at least i dont think so). when driving on the highway 95+% of the time we only get 21.5 MPG. i was wondering why the RPMs were so high at 2700 RPMs at 70MPH. that seems a little high to me b/c my 98 grand prix at 70 MPH is only at 21-2200 RPMs.

we recently had the transmission repaired b/c, according to the mechanic, it was not going into 4th gear or overdrive. when we got it back the rpms remained nearly the same as did the mpg.

so i was wondering if people could put some input as to what their rpms levels are like at various speeds just to see how we compare.

we also suspect the EGR valve is bad, too. but that shouldnt effect RPMs should it?

much appreciated!