Dina

I have got a used 2005 Mustang recently and the mileage seems to be very low around 11 to 12 mpg.. Is there any reason for this? Also, is there any way that I can increase the mpg.. Suggestions pls..

jwharton

Are you going by the onboard computer or hand calculating? Also what are your mods? Oh and welcome to the site!

Nuke

Yes, Welcome.

First, I'd validate that the speedometer is accurate with a GPS. If the previous owner did anything that would affect any of the parameters that the on-board uses to do its calcs (gears, tire O.D...) without adjusting the PCM settings, then any calculations are useless.

What's your driving like? If it's a lot of stop and go and short trips with a some aggressiveness, 11-12 is a good possibility. But if you're speedometer is accurate, then there are a few things to look into; the first being tire pressure (32 PSI is a good place to start). How many miles are on the car? Does it need new plugs? Are the brakes dragging? Fuel filter replacement? TB cleaning? Lots that we need to know.

Dina

It has got 69700 miles. Timing Chain.. And I do very short trips like say 3 to 4 miles to commute to office one way.. Before buying I did Firestone check and everything was GREEN. Firestone did not advice to change anything now. But planning to check fluids next week. And, Thanks for the invite

Nuke

I bought my g/f an '06 Pony (V6) and she drove a lot of 1-2 mile short trips to work and the store with a lot of traffic lights. She's lead-footed and was lucky to get 16 MPG with her V6 so 11-12 doesn't terribly surprise me. I'd be sure to check the tire pressure and try doing as much coasting to lights and gentle acceleration as possible. You might see 14-16 around town under those conditions with the vehicle up-to-snuff and some granny driving attitude.

Also, those short trips are tough on the battery and it never gets a chance to recoupe what it used to start the engine, especially on our weak charging systems. Keep an eye (or ear) on the cranking speed. As the battery loses charge the engine will crank a bit slower; a telltale sign to have the battery load tested (free at most auto parts stores).

Dina

Thanks for the reply.. I will try to check the tire pressure first.. Will be very happy if I get 14 or 15.. Will see.. Thanks..

alkemist

Driving manual or auto? If it's manual, maybe your RPM's are running higher than necessary.

Lowest I get is 15.xx for suburban driving (including many stop and go's) and 18.xx max. This is driving an auto with 4.10 gear and being tuned.

Gidyupp

At the track I managed 6.4 MPG

Dina

Driving automatic..

jimj3125

Just filled up and checked my mileage. Went a little under 300 miles(none freeway) and using the onboard computer reading of 22.2mpg. I also checked it using my calculator and got 22.2mpg. I am going to check it again tomorrow on a short highway trip of about 250 miles.
By the way the 22.2 miles was on the performance tune. The trip tomorrow will be using the stock tune.