MPG

[MDADDYRABBIT]

I have 305 tires. I just wonder if the MPG thingy in the instruments is right?

 

[TotallyHucked]

305 what? 305/55/20? 305/40/22? What load range? Tire height and weight play a huge factor in fuel mileage. And if they're considerably different size from stock, your computer is definitely not correct. It won't be unless you get it reflashed for the new tire size

 

[MDADDYRABBIT]

Waiting on wife to get home to see tire size exactly. I they are bigger then stock. How do I reflash the computer?

 

[FF376]

14 in mixed driving , 18 on highway. Stock tires and 3:73 gears

 

[06 Dodge]

Yesterday the wife and I took my truck on a 4 hour drive to the coast 178.5 miles, it tipped the scales at just under 11K, it used 9.101 gallons of diesel, our over all average speed was 44 mph...

 

[Nickx86]

2016 got 10 in town and 16 highway. Then the transfer case got flooded out and was getting 10 highway. 2022 gets about 11 city and 16-17 highway, 9 with the trailer loaded up. If Im taking the truck to my daytime job, i get like 14. I drive like I stole it thru traffic near NYC. My normal commute car get 32-35 mpg. 120 miles/day

 

[jejb]

I have 305 tires. I just wonder if the MPG thingy in the instruments is right?

If you have different than stock sized tires and it has not been corrected electronically, your odo/speedo and mpg readout will all be inaccurate.

 

[MDADDYRABBIT]

If you have different than stock sized tires and it has not been corrected electronically, your odo/speedo and mpg readout will all be inaccurate.

How do I fix that?

 

[mtnrider]

How do I fix that?

AlfaOBD can adjust the tire size.

 

[NETim]

Even if you correct for tire size, I'd hand calculate your mileage. I've found that trip computers can be notoriously optimistic.

 

[TotallyHucked]

Waiting on wife to get home to see tire size exactly. I they are bigger then stock. How do I reflash the computer?

Either with the AlfaOBD app, you can change the tire size in there. Or you can get the truck tuned by a reputable tuner but that's very expensive

 

[Dean2]

Either with the AlfaOBD app, you can change the tire size in there. Or you can get the truck tuned by a reputable tuner but that's very expensive

Most dealers, and many tire shops, have the ability to set your tire sizes so the Speedo etc read correctly.

 

[MDADDYRABBIT]

Anyone here done this your self?

 

[Dean2]

Anyone here done this your self?

Search it on here, there is lots of info on the AlphaOBD threads on how to do this.

 

[MDADDYRABBIT]

Search it on here, there is lots of info on the AlphaOBD threads on how to do this.

I am on it now, like a bloodhound

 

[vcolper]

2 miles? Tell your wife to walk or ride a bike to work.

 

[Units]

2 miles? Tell your wife to walk or ride a bike to work.

Some of us like to not have to sleep with one eye open!

 

[2003F350]

Some of us like to not have to sleep with one eye open!

Agreed, I'd never want my wife to walk or bike to work, especially if it was a higher-traffic area.

That said, it might be a good idea to look into a different vehicle...this is a PRIME example of when an EV would be useful.

 

[MDADDYRABBIT]

Agreed, I'd never want my wife to walk or bike to work, especially if it was a higher-traffic area.

That said, it might be a good idea to look into a different vehicle...this is a PRIME example of when an EV would be useful.

Not really wanting another vehicle. I hate car payments, more insurance cost, property tax cost. I just want the MPG monitor on the instrument panel to read as close to accurate as possible.

 

[2003F350]

Not really wanting another vehicle. I hate car payments, more insurance cost, property tax cost. I just want the MPG monitor on the instrument panel to read as close to accurate as possible.

As many have pointed out, it probably IS reading relatively accurately for how it's being driven. The 6.4 is not a 2-mile commuter engine. It is a gas workhorse, and you're probably barely getting to speed before you're slowing down again, and it's NEVER getting up to operating temperature. It's definitely not getting hot enough to burn off deposits in the catalytic converter unless you're taking it out on longer drives.

I get not wanting a payment or more insurance, but you really need to ask yourself if you need that truck, and if it is the vehicle that makes the most sense for her to drive back and forth to work in? If I were in your situation, the answer would most definitely be no, and I'd probably look into at least a hybrid, probably an EV for her (and she'd likely be okay with it, she likes the Lightning). That said, we always have an extra vehicle too, just in case we run into problems. One of us will get it out every now and then and drive it for a few days, just to keep things lubricated.