Fuel Economy

[Myles Cyncora]

Hello everyone.
I'm wondering what kind of fuel economy you guys are getting. I know these trucks aren't best in this area I just want to know if mine is getting the same as someone else or if something is wrong. 2008 Sport 4x4 4.0L auto 3.73s with as far as I know stock 255/70R16s. I filled up yesterday at 197.3 KMS on 25.25 LITERS of fuel equals 12.798 Liters per 100kms or 18.379 mpg. Does that sound about right or low for this truck?

 

[Dirtman]

Can you translate those units of measurement into dumb people math?

 

[Myles Cyncora]

If i did the conversion right thats 118.2 miles on 6.82 gallons equals 17.33 Mpg

 

[fastpakr]

Your first 18.38 number sounds right to me, and that seems reasonable for a 4.0.

 

[RonD]

18/19 MPG is good for any 4x4, also good for 2008 Ranger 4.0l V6 4x4

Problem with pickup trucks is that they sit higher and have wider tires usually, and 4x4s even more so
Wind resistance = lower MPG, a car sit lower so air flow under the vehicle is minimal, less resistance
The higher a vehicle sits the more air resistance it has, and usually the wider tires it has

Tire width = friction, wider tires have more friction, but friction is also traction
The more friction the lower the MPG, but the better the traction, so its a trade off
Smaller tires also weigh less, and of course the less weight you have to move the less fuel you need to move it

 

[Myles Cyncora]

For sure that makes sense and I understand that. Im asking this cause I am wondering if one of the calipers is starting to seize. Front left is the suspected one or does that one work harder cause its closer to the master cylinder.

 

[Dirtman]

Is one wheel significantly hotter than the other after going for a drive?

 

[Myles Cyncora]

Oh yeah that one is burning hot compared to any other brake. I dont have a thermometer but I can rest my hand on the front right brake and its a little warm but the front left I dont wantcto get my hand anywhwre near it.

 

[Dirtman]

Than yea either the hose has failed, caliper is sticking, or slide pins are frozen.

 

[Myles Cyncora]

Hose has failed? As in there could be a leak in the hose? If that is what you mean there is no leak that I have noticed.

 

[Dirtman]

Hose has failed? As in there could be a leak in the hose? If that is what you mean there is no leak that I have noticed.

No, when a brake hose fails internally it collapses. Not visible from the outside. When you apply the brakes the pressure opens it and allows normal braking but when you take your foot off the pedal the hose collapses again and does not allow the fluid to move back and release the piston. Essentially it causes the brake hose to act as a check valve...

 

[RonD]

He means the flex hose on that wheel, it can fail internally and act as a valve not releasing that caliper

Caliper piston(s) sticking is far more likely

Brake system uses hydraulics(fluid) so BOTH front wheel calipers get exactly the same pressure, distance from master doesn't matter, just an FYI

Rear brakes get less pressure, on purpose, thru a proportioning valve
Pickup trucks used 70/30, 70% to front and 30% to rear
Cars and SUVs use 60/40 proportioning

 

[Myles Cyncora]

Hmmm ok thanks. Sounds like I need to get it looked at.

 

[Dirtman]

Fairly simple to determine if its the caliper or brake hose. Jack the truck up, remove the wheel and then pump the brakes a bunch of times. Try to spin the rotor, if its hard to spin or won't move loosen the brake bleeder. If the rotor now spins freely you have a bad brake hose, if it's still stuck you have a bad caliper or frozen slides. Like Ron said a bad caliper is more likely than a bad hose but it's better to test than just replace parts.

 

[Myles Cyncora]

Thank you for how to test those items but I dont think ill be able to do that for about 2 weeks then it'll be ag least another week to get whichever replaced.