Serious gas milage issue
 

Hey everyone! I'm new to the forums! I purchased a 2005 Rx8 earlier this year with a manual transmission. When I purchased the car it had a little over 20k miles on it.

Right now it has 38k miles and I've noticed that I average at about 13-14mpg... The only aftermarket part is an aem cold air intake. I drove from Duluth, Minnesota to Fairfax, Virginia a few days ago. It was 1,200 miles, and I had to stop for gas six or seven times. I had the cruise control set at between 70-80mph... Is there something seriously wrong? Thanks for your help!

I'm not complaining.. I don't mind getting 13mpg. There is a lot of worse ways to spend money. I just want to know if I should take it in for a tune up? When I bought the car I wasn't expecting to get more than 20mpg highway

13-14 mpg on the freeway at those speeds means that something is seriously wrong. Fuel economy should be by no means that low.

yeah that seems odd when I travel from Minneapolis to Milwaukee I usually get around 300 miles to tank before the light turns on.

Gonna do the usual recommend you to reset the PCM/ECU(I think that's what it is). This causes your car to re-learn the fuel trims. Turn your key to the ON position and go nuts on your brake pedal(20 times) - you should see the oil pressure gauge sweep up and back down to 0.

Also how are your plugs/coils/wires? Have they ever been changed?

how much gas did you fill up with total and what were your start adn finish odo readings?

When was the last time the plugs/coils were changed?

Actually, when was the last time ANY of the general maintenance items were inspected??

Suggestions,

run through the threads in my sig, specifically the $100 thread for a car that age. Then, as soon as done with that, likely coils, then plugs. All cleaned up, she should do 20 or so at that speed, maybe more without cruise control.