2008 4.0L MPG hunt | Ford Explorer Forums - Serious Explorations

  • Register Today It's free!

2008 4.0L MPG hunt

Fredness

Elite Explorer
Joined
June 2, 2000
Messages
664
Reaction score
38
City, State
Tejas!
Year, Model & Trim Level
'05 Sport Trac Adrenalin
This is a customer's vehicle with 32,000 miles and as long as I don't post identifying images/info they agreed to let me do testing since the vehicle was out of service until next week.
Now, before anyone gets nit-picky, this is somewhat anecdotal as there is no controlled environment and no "control" vehicle for comparison - all results are "non-scientific", but repeatable.

Lease return that had all maintenance covered until recently. 5K on the clock since last oil change (Dino oil) - Not a severe duty vehicle, so that's fine.

They are complaining about gas mileage (who isn't these days?), their average: 14.4MPG (see image 1):
I chose to start with the obvious; the data - garbage in, garbage out and all...
Customer is basing the MPG on the MPG display from the PCM, since the have gone to a +6 size (22's :p: ), I started with the odometer - >1% speedo error, actually closer than factory specs. GPS confirmed, not it.

Next, the Driver.
I took this on the same route, and with the usual changes: light throttle, plan actions by looking further ahead, use cruise control as much as possible, reduce braking and keep it at 60MPH or less. This nets a nice 29% increase to 18.6MPG (image 2).

Next is Routine Maintenance.
We go to the source, the Motorcraft Service site (non-applicable items removed for brevity):
❑ Change engine oil and replace oil filter - **
❑ Inspect automatic transmission/transaxle fluid level on all other vehicles if equipped with dipstick. Consult your dealer for particular requirements.
❑ Replace engine air filter - ***
❑ Replace fuel filter - **
❑ Inspect steering linkage, suspension and, if equipped, driveshaft, ball joints and U-joints
❑ Inspect engine cooling system and hoses
❑ Inspect brake pads, shoes, rotors, drums, brake lines and hoses and parking brake system. - **
❑ Inspect exhaust system and heat shields
❑ Lubricate ball joints and U-joints (if equipped with zerk fittings)
❑ Perform multi-point inspection (recommended)
❑ Rotate tires, inspect tires for wear and measure tread depth - **
❑ Inspect wheels for end play and noise - *

Each asterisk is how much I expect the item to improve

Air Filter is the easiest, and with 32,000 on the clock and Motorcraft's blessing (image 3), we see an additional 6% increase (image 4).

If you care, stay tuned for Oil/Filter and Fuel Filter. I'll also add any surprises, like the TPMS Fault because the new rims and tires were installed without sensors!
 

Attachments

  • MPG_ST_Start.jpg
    MPG_ST_Start.jpg
    54.1 KB · Views: 789
  • MPG_ST_Driver.jpg
    MPG_ST_Driver.jpg
    50.2 KB · Views: 774
  • MPG_ST_AF.jpg
    MPG_ST_AF.jpg
    141.8 KB · Views: 830
  • MPG_ST_Air_filter.jpg
    MPG_ST_Air_filter.jpg
    35.2 KB · Views: 790



Join the Elite Explorers for $20 each year.
Elite Explorer members see no advertisements, no banner ads, no double underlined links,.
Add an avatar, upload photo attachments, and more!
.





Nice, I get around 18mpg with 255 Grabber AT2s and conservative use of the accelerator. I almost got it up to 19.8mpg back before I had 255 Grabbers. Only other mod is K&N Filter.
 






Mine has a K&N drop-in and a Gibson exhaust, and FWIW I run Mobil 1 0w-30 Fuel Economy Formula. City mpg was never good, I usually average 14.7 on every tank. That said, if I'm on the highway with the cruise set on 65 I'll get 21 to 23, truck is rated at 19 hwy. If I run 75 the mpg drops to 16 to 17.

My .02, the big tires on your customer's truck are hurting it more than anything.
 






The tires are stock size (in diameter), just on 40 series profile on 22's.
But yeah, you can REALLY feel it in the brakes, they just aren't there pedal vs. response wise. My '05 is FAR better braking even w/o traction control.
 






Well, how wide your tires are will also affect the mileage (if you gave ---/--R22 it would help).
 






This is a customer's vehicle with 32,000 miles and as long as I don't post identifying images/info they agreed to let me do testing since the vehicle was out of service until next week.
Now, before anyone gets nit-picky, this is somewhat anecdotal as there is no controlled environment and no "control" vehicle for comparison - all results are "non-scientific", but repeatable.

Lease return that had all maintenance covered until recently. 5K on the clock since last oil change (Dino oil) - Not a severe duty vehicle, so that's fine.

They are complaining about gas mileage (who isn't these days?), their average: 14.4MPG (see image 1):
I chose to start with the obvious; the data - garbage in, garbage out and all...
Customer is basing the MPG on the MPG display from the PCM, since the have gone to a +6 size (22's :p: ), I started with the odometer - >1% speedo error, actually closer than factory specs. GPS confirmed, not it.

Next, the Driver.
I took this on the same route, and with the usual changes: light throttle, plan actions by looking further ahead, use cruise control as much as possible, reduce braking and keep it at 60MPH or less. This nets a nice 29% increase to 18.6MPG (image 2).

Next is Routine Maintenance.
We go to the source, the Motorcraft Service site (non-applicable items removed for brevity):
❑ Change engine oil and replace oil filter - **
❑ Inspect automatic transmission/transaxle fluid level on all other vehicles if equipped with dipstick. Consult your dealer for particular requirements.
❑ Replace engine air filter - ***
❑ Replace fuel filter - **
❑ Inspect steering linkage, suspension and, if equipped, driveshaft, ball joints and U-joints
❑ Inspect engine cooling system and hoses
❑ Inspect brake pads, shoes, rotors, drums, brake lines and hoses and parking brake system. - **
❑ Inspect exhaust system and heat shields
❑ Lubricate ball joints and U-joints (if equipped with zerk fittings)
❑ Perform multi-point inspection (recommended)
❑ Rotate tires, inspect tires for wear and measure tread depth - **
❑ Inspect wheels for end play and noise - *

Each asterisk is how much I expect the item to improve

Air Filter is the easiest, and with 32,000 on the clock and Motorcraft's blessing (image 3), we see an additional 6% increase (image 4).

If you care, stay tuned for Oil/Filter and Fuel Filter. I'll also add any surprises, like the TPMS Fault because the new rims and tires were installed without sensors!

BIG GRINS... great job showing us how easy it really can be. Thanks !!!
 






I know my ST doesn't apply to this thread, but I have to second the thanks for this post. Good stuff! :thumbsup:

I would LOVE to get 14.4 MPG. I'm currently hangin around 11.5 MPG :(
 






Crap man, going to gas up must be pain - I hate it enough and I hardly have to (I don't drive much these days, ST's being a bit of pavement ornament).
 












Well, how wide your tires are will also affect the mileage (if you gave ---/--R22 it would help).

+1. Wider tires have more rolling resistance. The type of tire matters too. I lost 1 to 2 mpg when I went from the OE all-season tires to all-terrain tires (stock size). The OE Goodyears were so horrible in snow however that I'm lucky I didn't wreck it a couple of times.
 






If you got something with a smaller 1st number (like how 235s are stock) that will have them be less wide (assuming you don't get an MT tread), and that'll bump the MPG up.
 






Yeah, but the customer is (currently) more caught up in "looks" than MPG - I'm sure with time, that will change - like when gas hits $5+ this summer.
My recommendation was actually 18" Gunmetal Cobra's with 235/60R18's. They are lower profile than stock, similar width and much more "streetable". You won't feel every crack in the road with them like you do the 40's.
But, these tires are new and have plenty of tread. We'll see where they go next time.
 






Bah Bah! Heresy! Speak of such things not! I am currently accepting the likely fact that gas will be $4.00 this summer (unless "Sasquatch Country" is CA, in which case I wouldn't be surprised - prices there are a good +25% higher than everybody else on a normal basis).
Anyway...
 






:wtf:
Bah Bah! Heresy! Speak of such things not!
[Spits on ground, turns clockwise 3 times, kicks a black cat and throws salt over shoulder]
Yeah, it's gonna suck. :wtf:
I'm Seattle-ish.
 






My recommendation was actually 18" Gunmetal Cobra's with 235/60R18's.

235/65-18's are a factory optional size on Gen 2's.
 






...but they can use the 235/60R18's with no change in the speedo.
The 235/65-18's will show 3.57% too slow on the speedo and require a flash tuner, recalibration or Ford reflash to correct the speedo, tire size and N/V [how the trans shifts].
Since they are (now) running an X3, the 65's are an option as well, the taller tire should help with MPGs by reducing the effective gear ratio.

Fuel Filter, oil change and radiator overflow crack repaired. Need to do one more mileage check before I flash a tune on it.
 






I found by not pressing the gas pedal to the floor I picked up 5 mpg. Nice and soft starts get 18 city and 22 freeway. My wife gets even better when she drives it.
 






...but they can use the 235/60R18's with no change in the speedo.
The 235/65-18's will show 3.57% too slow on the speedo and require a flash tuner, recalibration or Ford reflash to correct the speedo, tire size and N/V [how the trans shifts].

Mine has 245/65-17's (OE size) and shows about that slow on the speedo compared to the GPS as well. I'm thinking of getting a tuner to improve the city mpg, if anybody got an improvement from that let me know. I'll get 22 mpg on the highway if I keep it to 65 mph because of the exhaust, it's rated at 19 hwy, so I don't think that will improve much more.
 






im only doing 11.8 in the city.. i just put it in a k&N drop filter. did a complete tune up and brought new tires... can someone tell me what i am doing wrong here??
 



Join the Elite Explorers for $20 each year.
Elite Explorer members see no advertisements, no banner ads, no double underlined links,.
Add an avatar, upload photo attachments, and more!
.





Mashing the pedal maybe? Maybe getting stuck in a lot of traffic?
How often do you go above 3000RPM?
 






Back
Top