Speedometer/MPG/Miles read out

GulfCoastBronco

Outer Banks
Well-Known Member
First Name
Topher
Joined
Jan 29, 2022
Threads
25
Messages
331
Reaction score
582
Location
Corpus
Vehicle(s)
Bronco Sport
Question of curiosity. If putting larger tires causes speedometer to be off without calibration, is the “live” mpg read out also different? What about the odometer read out? Would that be effected as well? Does my vehicle possibly have a different number of actual miles on it due to different size tires?
Sponsored

 

Meanderthal

Badlands
Well-Known Member
First Name
Eric
Joined
Mar 19, 2022
Threads
10
Messages
2,008
Reaction score
2,760
Location
Colorado
Vehicle(s)
'08 BMW R1200 GS Adv, '23 Norden Expedition
Question of curiosity. If putting larger tires causes speedometer to be off without calibration, is the “live” mpg read out also different? What about the odometer read out? Would that be effected as well? Does my vehicle possibly have a different number of actual miles on it due to different size tires?
is the “live” mpg read out also different? Yes
What about the odometer read out? Yes
Would that be effected as well? Yes
Does my vehicle possibly have a different number of actual miles on it due to different size tires? Yes

All of these things are off but by a pretty small percent.
 

rdc17

Badlands
Well-Known Member
Joined
Dec 18, 2020
Threads
7
Messages
300
Reaction score
393
Location
VA
Vehicle(s)
BL+BL
Yes, putting on larger tires will cause your odometer to undercount your miles driven and your MPG readout to be less than what you're actually getting. The MPG readout will drop because the car thinks you're using the same amount of fuel as before to travel less distance then you actually are.

I went from 225 to 245 and my MPG readout would rarely top 22 combined. Finally reprogramed the tire size this summer with Forscan and I've been holding steady slightly over 25mpg combined for the last few months. Before I did that, I did hand calculations on real world MPG and I found that I was getting closer to 24.
 

Escape2Bronco

Badlands
Well-Known Member
First Name
Steve
Joined
Oct 9, 2021
Threads
4
Messages
2,637
Reaction score
3,293
Location
Wisconsin
Vehicle(s)
2013 Lexus, 2022 Bronco Sport, 2023 Heritage 2 dr
Question of curiosity. If putting larger tires causes speedometer to be off without calibration, is the “live” mpg read out also different? What about the odometer read out? Would that be effected as well? Does my vehicle possibly have a different number of actual miles on it due to different size tires?
Yes, they will all be off. You can go to Tire Rack and compare your tires to the ones you want. It will give you all the information on the sizes. As for MPG.....your mileage will vary. Assuming you are going bigger and heavier, your MPG will suffer both in reading and in actuality. As Eric said, its not by a lot but it will change depending on the size difference.
 

Dperry285

Outer Banks
Well-Known Member
First Name
Dennis
Joined
Dec 17, 2022
Threads
12
Messages
85
Reaction score
31
Location
44024
Vehicle(s)
2023 ford bronco sport
Question of curiosity. If putting larger tires causes speedometer to be off without calibration, is the “live” mpg read out also different? What about the odometer read out? Would that be effected as well? Does my vehicle possibly have a different number of actual miles on it due to different size tires?
Yes
 

Bucko

Outer Banks
Well-Known Member
First Name
Kevin
Joined
Mar 16, 2023
Threads
44
Messages
1,812
Reaction score
2,474
Location
Gainesville
Vehicle(s)
2023 Ford Bronco Sport
 




Top