Royderjd

i recently bought a used 2010 XLT 5.4L 4x4 SuperCrew. From the get go it just has gotten the Highway gas mileage I was expecting. I'm currently getting around 13MPG on the highway @ posted speed limits from 70 to 75 mph. Am i doomed to keep getting this MPG or do you'll think this is alittle low.

i know from the looks of things with the truck that the pervious owners had done some Mods and removed them. Mainly simple stuff like aftermarket stereo and removed start. but they removed them which I can only figure that they were probably having problems with them. This is as far I'm going to assume on that. but if they would install stuff like that and take it off before trading it in. makes me wonder whatelse they did to it.

any ideas on why my MPG is a littler lower then desired of like 16 on the highway or maybe alittle better.

oh also i noticed that the tires on the truck are 275/65R20 the sticker on the doors says the tire size should be 275/55R20. so once again i dont know if the truck came like this or if they got these and replaced the factory tires and size, possible never having the comp recalibrated for the little bit bigger tire size.

gDMJoe

Depending upon mileage and when maintenace was last done ...

• clean the MAF sensor.
• new air filter.
• check front-end suspension components and alignment.
• check tire air pressure and adjust accordingly to spec'.
• remove any unnecessary cab' and/or bed clutter.
• use cruise control.
• use overdrive (if equipped) unless towing.
• insure dif', transfer case fluid levels are full.
• avoid prolonged start-up warm-ups and/or idling.
• easy on the gas pedal at take-off and anticipate stops.

Regarding tire size ...

• due to the smaller contact patch, the 275/65R20 should give you slightly better MPG.
  .
• 275/65R20 is NOT the standard size and your speedometer may be 6.8% slow (speedo = 60MPH, actual = 64MPH). This would mean that your MPG was also low -UNLESS- the PCM had been flashed to compensate for the tire size change.

Royderjd

yes i understand all that, and have checked over most of that the air filter is a good to check i just havent done it and kind of expected the dealership to take care of that.

but as far as i remember the contact patch(K-patch) shouldnt be effected but having a taller tire.

rbrais

Sometimes they really go through a vehicle; sometimes just put it on the lot and see if it comes back with an issue. Depends on the dealership.

That is pretty low. I'm getting 12 mpg with 35" tires on an 11 year old truck. How heavy is your foot? That can have a big affect on MPG.

Stock (5.4L) I was getting 14 mpg with a light foot.

bigburns12

Does cleaning the MAF have a lot to do with it?

gDMJoe

The aspect ratio of the tires (65 versus 55) makes the contact patch of the of the 65 series smaller via the difference in thread width: 8.7" versus 9.5". *The length is probably near the same.

Apologies if any/all of the info' was of no earthly use. Carry on ...

We return you to your regularly scheduled programming ....
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gDMJoe

Can and does if it's contaminated.
.

bigburns12

So do you think just pulling it out and spraying generic maf cleaner would work?

Royderjd

Was that 14 around town or Highway?

ummm my foot since i got the truck ive been keeping a light foot and pretty much every where i go i use the good old cruise control.

Royderjd

i wouldnt use anything super harsh like carb cleaner but i dont think some brake clean wouldnt hurt it make sure it drys before you put it back in and start your truck.