Ford Tough - Home of Canadian Ford Truck Enthusiasts banner

Inaccurate odometer

4845 Views 25 Replies 8 Participants Last post by  Destructicon
Hey all, i discovered an issue with my odometer today. i drove thru a measured km section on the highway and my odo read 3 km on a 5 km test section. As far as i know the drivetrain is completely stock. the only thing i have changed is the gauge cluster itself, swapped one with a tach in it also from a 97 . tires on it now are stock size tho i do run a larger tire in the summer but still on 16in. rims. stock is 235/70r-16, summer's are 265/75r-16. Did going larger confuse the computer? the speedo seems to be accurate so i am a little confused as to why there is such a difference in the odo. It does explain why my mileage seemed to be so bad. Any ideas? thanks..
1 - 20 of 26 Posts
Seeing that you get 3km's on a 5km stretch, add in the fact that you changed the cluster, I would think that the cluster is believing you are in miles per hour. Do you know if the cluster came from an American truck?
Did you get the cluster out of a truck with the same gear ratio?
The cluster came out of a truck that had a v-8 & auto trans but not sure of gear ratio. the american angle is making sense because the mph is the predominant numbers on the gauge face. is there a way to change it to reading km? Great suggestions btw, never would have thought of that.
I know you can change from mph to kph (or the other way) in my super duty pretty easy. But your truck, I'm not sure...and I forget how to do it on mine anyway! lol.
well now that i know it is in mph i can still figure out what my actual mileage is and be able to calculate gas mileage accurately. if i switch to km now i will really confuse the shit out of myself!
haha
Which gallon will you use to calculate?
huh?
which gallon will you use to calculate?
3.78

hopefully your not doing 60mph in a 60 km/h zone.
US or Imperial;)
can i just convert miles to km then divide by litres used?
Imperial gallon (4.546 litres) vs US gallon (3.78 litres).

You get better mileage numbers with the smaller US gallon. lol

Or, convert your litres used into gallons and figure miles per gallon.

Sounds like too much work to me, probably why I could give a shit about gas mileage with a full size pickup truck that weighs 6300 lbs.
Imperial gallon (4.546 litres) vs US gallon (3.78 litres).

You get better mileage numbers with the smaller US gallon. lol

Or, convert your litres used into gallons and figure miles per gallon.

Sounds like too much work to me, probably why I could give a shit about gas mileage with a full size pickup truck that weighs 6300 lbs.
you are absolutely right. i have enough in life that hurts my head why add more. thanks to all for helping me with this
Imperial gallon (4.546 litres) vs US gallon (3.78 litres).

You get better mileage numbers with the smaller US gallon. lol

Or, convert your litres used into gallons and figure miles per gallon.

Sounds like too much work to me, probably why I could give a shit about gas mileage with a full size pickup truck that weighs 6300 lbs.
wrong you get better numbers using the imperial gallon then the us.
last fill up of 94 octane. 9.92 MPG USA = 11.5 MPG canadian = 20.52 l/100km
all done with an app that cost 99c and keeps track of all my fillups and maintenance
A 235/70r-16 is 29" tall and a 265/75r-16 is 31.6" tall, when you changed your tire size did you change your speedometer gear as well so it would read accurate?
wrong you get better numbers using the imperial gallon then the us.
last fill up of 94 octane. 9.92 MPG USA = 11.5 MPG canadian = 20.52 l/100km
all done with an app that cost 99c and keeps track of all my fillups and maintenance

This is going to sound retarded, but I'm going to argue the point anyway.



If I fill my tank with 25 gallons US, that's 94.5 litres.

If I fill the tank with 25 gallons Imperial, that's 113.65 litres.



If the odometer says I went 500 km since my last fill up, on a gallon per gallon comparison, numbers wise , my mileage would be better using the US gallon.

However, to get the same volume in my tank, I would have to pump another 19.15 litres to get the same amount of gas in the tank with the US gallon, if that makes sense.


In that case, your argument would be valid, and your numbers would be better using the Imperial gallon, because it takes less Imperial gallons to fill your tank than US gallons.



See that Blair ? We're both right. lol This is yet another reason why I don't give a shit about gas mileage.

Incidentally, I'm not sure where my head was at, but you're right, good on you for calling me out, I would expect no less.
See less See more
I didn't read your answer.


Sent from my iPhone using Tapatalk
Go back, I just posted it up one minute earlier.

If you mean you ignored my answer, that's OK too, it's painful.
OMG! Would it not be better to put in the proper gauge pack and calculate L\100km? This is Canada. We switched to metric years ago. Get used to it. Fill the tank to the lid. Drive 500km. Fill the tank to the lid again. Take the number of liters and divide by 5. Simple. Lower numbers are better. ie...8L/100km is better than 15L/100km. And check the gear ratio. It's meaningless if your running 3.08 gears and got the gauge set out of something with 4.10 gears. That much of a tire size difference will affect your speedo and odo. It will be out by more, the faster you go. ie...50km/h may actually be 54km/h, a 4 km/h difference but 100km/h may be 110km/h, a 10km/h difference.
1 - 20 of 26 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top