Not real happy about mileage now!

[GSD]

When I first got my X (used 01) with no mods, had 4 adults and two kids in it, doing 80 mph with the trip comp saying I was averaging 19 MPG!

Then I buy the 4" exhaust and did the Air intake mod, now only going 70 MPH with just me and the wife the same little trip comp says I average 16.3 at best!

 

[Swany]

do the hand calculation, the computers are usually off (especially if you added a programmer)

 

[95_stroker]

Winter blend fuel?

 

[95_stroker]

In addition, I dont know that I beleive 19 mpg @ 80 either. Not that I dont believe you, I dont believe your trip comp. 16~17 sounds way more reasonable to me.......

 

[Swany]

or you or your wife put on some serious poundage?

 

[GSD]

Yeah, I sure did after Cancún!


But when hand calculating it, it was still relative, it got better mileage before messing with it!

Sounds cooler now, but why would either of those two things make it worse?

 

[_CH_]

heavier foot now?

 

[drchris1024]

In addition, I dont know that I beleive 19 mpg @ 80 either. Not that I dont believe you, I dont believe your trip comp. 16~17 sounds way more reasonable to me.......

I'd have to agree, that seems high. mine mpg tapers off alot going any where above 2000rpm/ 70mph. do you have 2x4 / 4x4 ?

 

[CHPMustang]

Exhaust and intake won't cut it for best MPG's but helps performance some.

I recommend bumping the fuel pressure,install an HX,remove the Intake Air Heater and take a 2" holesaw to do three holes on the radiator support panel blocking the air intake tube opening's airflow.

Do those low cost mods and they should benefit better MPG numbers as well as performance

Check/bump your tire pressure and a programmer will help MPG's also

Freeway non-tow we're doing 20-21+MPG at 65-70 MPH depending on road grade.

 

[DR.billZ]

I'd double the "check the tire pressure" especially if you took it in anywhere to have service done. Rarely do you find a regular mechanic that knows it is right to have over 55psi in your tires. I used to 75 in my F-350 all the time.