Hi all, I recently filled up the Disco, i always put in super 91, anyway i filled up 19.5 gallons and i had only driven 175 miles. I never really paid attention to mpg until recently. I calculated that to be around 9mpg, just so everyone knows i am a very conservative driver, usually not over 2500 rpm, i mostly drive city. But it shouldn't be this bad i mean common... All my fluids are good, one of the mufflers has a subtle vibration when im idling, but other than that what could be causing this! Thanks in advance.

 

Dirty air filter, tire PSI to low, need of a tune up, bad O2 sensors,. mother in law in the back seat.
Start with those things.

 

Air filter good, psi fine, how to I check my O2 sensors, and what intails a tune up besides plugs and wires?

 

What do you mean by PSI fine ??? I run 38 out back and 34 up front. some people run 40 all around, how about you ???

Make sure your emergency brake doesn't stick.

What's the mileage on your truck ???

 

Yes i have even psi all around, i didnt know much about how it affected it, but when i got new tires the mechanic told me that uneven tire pressure causes problems. But it seems the mpg did change when i got new tires.

 

I'd try plugs and wires. Still don't know how many miles ????

 

Sorry, 145,000

 

Having all fours tires at 20psi will cut your MPG HUGE, running them at 40psi will help your MPG.
So just saying that they tire PSI is fine is not very informative for us to help you.
You just got new tires, if they put them at 32psi (most tire shops do) then you need to pump them up.
If you got a M/T or a aggressive A/T installed than will drop MPG too.
A tune up is new plugs and wires.
No real way to test a O2, you just replace them.
Also running cheap gas will drop your MPG, and you can still get cheap gas even though it is premium (92 octane)
Stay away from the "discount" gas stations.

 

quit dropping the hammer at lights.

i get 14-15 mpg.

 

While standing in front of the truck facing the windshield - if you can see any of the following letters "DLNA RVORE" affixed to the hood; then the truck is equipped with the brickamus aerodynamicus option. This option results in city mpg's around 10.