Fuel economy and RPM of 99 Solary SE

[smatoska]

I've got a problem which may be a problem or not, but my rpm on my v-6 solara is 2900 at 75 mph. Is this normal? I changed spark plugs, wires, timing belt and pulleys, oil and air filters, but my mileage went from 30 mpg to 24 and rpm seems high. What could be the cause? The car runs smooth, has great acceleration, and no other problems, but I'm wondering what could be the culprit of the lower gas mileage?
I'm a DIYer and did all the work myself, so I'm kind of lost when in comes to knowing where to start with trying to get my mpg back....oh yes I did put a bottle of that marine soap??? into the gas tank for cleaning of intake and valves. Changed oil almost 1500 miles ago and when I checked it this week it was like new yet, which I really like because I've got over 107,000 miles on the engine.
Any help would be greatly appreciated!

[jhmesquire]

I had,,, have a very simaler problem. I replaced all sorts of stuff and it did'nt do me any good MPG gains better performance. I just replaced my gas cap and it brought me from 19mpg to 25mpg. aparently the cap is vented. It lets air in and keeps it in. I also had about 110k on my 2001. I would give it a try the cap from the dealer was like $12 i think you can get it for $6 at a parts store.

also you kight want to think about changing you tranny fluide. the dealler recomends doing it every 30k most poeple don't

on that note not many people change their fuel filters. its right bellow the air cleaner box, you will need some line wrenches, but i would sugest just paying the $50 and have some one else do it.

hope this helps