Why Is The Mileage So Bad On The Tremor?

[Gsxrdoug]

You all talk about this Highway thing a lot, not sure what that is, I get 16 mpg currently but only have 500 miles on it. And we really don't have any highways and the ones they call highways are just a little bit faster city streets.

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[D Fresh]

You all talk about this Highway thing a lot, not sure what that is, I get 16 mpg currently but only have 500 miles on it. And we really don't have any highways and the ones they call highways are just a little bit faster city streets.

Google image search for Hawaiian highway.

Doesn't look like the highways I drive on.

 

[XLT_TREMOR]

Google image search for Hawaiian highway.

Doesn't look like the highways I drive on.

Yeah 50mph on H-1 is ridiculous. Much of the surface streets around here are 45-55.

 

[typmoon]

I have almost 4000 miles on my Tremor. I notice the average the computer says is 21-23 MPG but when I do the math with the trip and amount of gas I fill it up with. I notice its off by a 2ish MPG. I dont mind the MPG but im curious why the Estimated MPG is off by that much.
Not sure if its because the speedometer doesn't take into account for the larger tire or not. When I look online about these tires, it doesn't list the size as a option which is odd but its whatever. I plan to get new wheels and tires in the near future

 

[awd.nv]

I have almost 4000 miles on my Tremor. I notice the average the computer says is 21-23 MPG but when I do the math with the trip and amount of gas I fill it up with. I notice its off by a 2ish MPG. I dont mind the MPG but im curious why the Estimated MPG is off by that much.
Not sure if its because the speedometer doesn't take into account for the larger tire or not. When I look online about these tires, it doesn't list the size as a option which is odd but its whatever. I plan to get new wheels and tires in the near future

I have noticed it is most accurate the less I stop. Meaning highway driving is most accurate. If I do a lot of city driving or what not then it is usually off 1-2MPG. Our '16 Honda Pilot is the same way. I basically just figure whatever the display shows, subtract 1-2mpg.

There was a thread somewhere in another sub forum here that showed how to calibrate it by changing a setting but don't remember where that was.

 

[BlackRanger01]

One of main reason why I didn't want to get tremor or fx4. I wont be taking them off road and couldn't care less about bragging rights so standard 4x4 with diff lock is good enough for me.

I've been getting around 22.1MPG according the trip1 I have not reset since I got it. 1800 miles now. Way better than I had monte and fusion when driving around town (they were getting 17 to 19). Haven't done much long trip highway driving as I go on highway every day but only a few miles.

 

[Megawatt]

I have almost 4000 miles on my Tremor. I notice the average the computer says is 21-23 MPG but when I do the math with the trip and amount of gas I fill it up with. I notice its off by a 2ish MPG. I dont mind the MPG but im curious why the Estimated MPG is off by that much.

I have noticed it is most accurate the less I stop. Meaning highway driving is most accurate….

Put the display to fuel economy. Every single second your foot is off the accelerator the computer uses 40mph for the fuel economy calculation. So the fuel economy mpg will always be higher than actual hand calculation of trip miles/actual number of gallons to fill the tank.

it is the reason why highway trip computer mpg is more accurate vs city driving mpg shown on the screen. All vehicles use an inflated mpg while coasting. I had a VW gti that defaulted to 200mpg when foot is off the accelerator. That computer mpg was always way off from hand calculations.

 

[awd.nv]

Put the display to fuel economy. Every single second your foot is off the accelerator the computer uses 40mph for the fuel economy calculation. So the fuel economy mpg will always be higher than actual hand calculation of trip miles/actual number of gallons to fill the tank.

it is the reason why highway trip computer mpg is more accurate vs city driving mpg shown on the screen. All vehicles use an inflated mpg while coasting. I had a VW gti that defaulted to 200mpg when foot is off the accelerator. That computer mpg was always way off from hand calculations.

Well, you know how long the Vegas red lights are but I still manage 14-16mpg display with usually a calculated 1-2mpg less haha. It makes sense though but all I look for is "Hey on average it is 1-2mpg over" so I factor that into my math when I am not interested in the math. I usually fill up every tank too, I just dont add it up every time.

 

[VegasRanger]

After leveling mine and switching to 265/70/17, I can't get better than 18mpg. That's mostly highway and using 91 octane.

 

[Gsxrdoug]

Oh I forgot to mention that's its a badass truck (Tremor) and those don't get good MPGs.

 

[Zvedza]

I get 19.3-19.6 handcalc'd
Screen says 21-21.5mpg
Some highway mixed in with 45-55mph roads for majority.
Stock setup with a soft bed cover, tire pressures @ cold 34psi, 93 octane. Florida summer weather.

Swapped to lighter wheels, but heavier and bigger tires and the screen is reporting roughly same mpg for "same" speed, once this tank is done gonna hand calc it, but i think that still may be off since these are taller tires. Prob change it in forscan this weekend then see what i get.

 

[Msfitoy]

Love to see TFL do a scientific stock vs modified mpg impact test...

1-start with stock truck, controlled mpg testing under specific conditions
2-increase tire size, test again
3-add wheel spacers, test again
4-level/lift, test again
5-add bed accessories, test again
6-add RTT, test again
7-add cargo weight to total 5,500#, test again
8-tow camper, test again

 

[awd.nv]

Love to see TFL do a scientific stock vs modified mpg impact test...

1-start with stock truck, controlled mpg testing under specific conditions
2-increase tire size, test again
3-add wheel spacers, test again
4-level/lift, test again
5-add bed accessories, test again
6-add RTT, test again
7-add cargo weight to total 5,500#, test again
8-tow camper, test again

I wish their towing test used Travel Trailers, their aero cargo trailer or flat beds they used just aren't the same as a massive brick/sail behind you.

Just comparing the Tremor sticker MPG vs the FX4 shows you a bit what a hit on MPG the tires and a slight lift over the FX4 will do. Not too surprised seeing how we lost MPG on our Pilot with a lift and tire swap....shoot the roof cargo basket accounted for 2-3mpg loss. More than the lift and tires.

 

[Dgc333]

Put the display to fuel economy. Every single second your foot is off the accelerator the computer uses 40mph for the fuel economy calculation. So the fuel economy mpg will always be higher than actual hand calculation of trip miles/actual number of gallons to fill the tank.

it is the reason why highway trip computer mpg is more accurate vs city driving mpg shown on the screen. All vehicles use an inflated mpg while coasting. I had a VW gti that defaulted to 200mpg when foot is off the accelerator. That computer mpg was always way off from hand calculations.

I don't understand what you are trying to say.

Every vehicle that I have had since the mid 80's with a trip computer worked the same way for the mpg calculations. It used the duty cycle of the fuel injectors to calculate the volume of fuel being consumed and the odometer for the mileage being driven. So average mpg between resets of the trip computer it is a simple miles driven divided by fuel consumed. It is always totaling miles driven and fuel consumed. Instantaneous mpg is calculated the same just using small slices of time.

Over the past 10 years or so the manufacturers have been shutting off the injectors when the vehicle is coasting specifically to save fuel and increase mileage. So during a coasting event you are still accumulating miles driven with no fuel being consumed resulting in the calculated mpg going up. Conversely when you are stopped with the engine running you are not accumulating any miles but are using fuel so the calculated mpg goes down. Another measure to increase mpg is the auto start/stop so you are not consuming fuel when the vehicle is not moving.

The fact that the display on the dash limits the range you see has nothing to do with the calculation going on in the background. It is just done to make the display more readable and/or prevent outlandish numbers numbers from being displayed.

Errors come from injectors varying from their nominal dimensions and/or fuel pressure varying from their nominal pressure. Over size injectors or higher fuel pressure will result in more fuel flowing than what a given duty cycle is programed for resulting in a higher reading than a hand calculation. The converse is true for less than nominal parts.

Another thing to keep in mind is a hand calculation is not absolutely accurate either and it is very easy to get a +/- 1 or more mpg error. The error comes from the fact that it is near impossible to consistently FILL the tank due variations in the pump, the cutoff in the nozzle or the way the nozzle hangs in the tank without topping off until fuel dribbles out the filler neck which is bad for the EVAP system.

I commend Ford for allowing you to adjust an offset to make the in vehicle display more accurate. If you plan to do that the most accurate way you would need to record the displayed mpg and the hand calculated mpg over a number of tanks (more the better). Then average the display numbers and the hand calculated numbers to come up with the numbers to use for calculating the office set. If you have done it accurately you will see the display and hand calculation alternating with the more optimistic number.

 

[XLT_TREMOR]

After my longest one way trip so far, I gotta say I’m impressed with the mileage possible. 142 mile trip with 4,000+ ft. elevation gain at the end. 23.5mpg overall and had a 24.8 average just before the climb from sea level. And that was with about a half hour of traffic crawling on the freeway to get past a couple of accidents in LA.

Nice to see the difference from my city use. Not that I care about the fuel economy so much, but I like range possible for longer trips. Lots of places I can get to with one fuel stop…more than I thought at least.

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