Differance, Not Sure

[69signetv8]

For you math guys or just in the know:
I kinda think there's a differance but I'm not 100% sure.

Since my 273 was rebuild and now pulled, I have noted that I have put on 21,886 miles in the past four years. I had 391 gears through out this time and didn't change the speedo gear (me bad). Due to this...of course speedo indication is different, that I know (like showing 85 MPH when only doing 55 MPH. Question: Does this mean my true mileage is recorded higher as well (like a mile is no longer a mile but shorter :scratch: If so....what would you "guess" as a closer true mileage number with my info above??
Added info: 28" tires and "about" 3200RPM @ true 55 MPH
Anyone want to try to figure.
Cheers and Thanks

 

[dusterdon]

be a lot easier if we knew what gear was in it before and if the speedo pinion was a good match for that gear.

 

['64 Cuda]

If what you stated about the speedo reading 85 when only going 55 is correct, & speedo was accurate before, then I think the math would be like this.

55/85 = .6470588

.6470588 x 21,886 = 14,161.5 miles.

This gives an approximation of the miles traveled by the vehicle, but since the engine was spinning faster, the 21,886 is a more accurate indication of the wear on the engine & trans, although they don't have to work quite as hard because of the mechanical advantage of the 3.91 gears. As far as tires, wheel bearings, brakes & the like, the lower mileage would apply. Somebody correct me if my reasoning is wacko. :violent1:


:burnout:

 

[69signetv8]

be a lot easier if we knew what gear was in it before and if the speedo pinion was a good match for that gear.

3:23 with matching speedo gear.

 

[69signetv8]

[QUOTE='64 Cuda]If what you stated about the speedo reading 85 when only going 55 is correct, & speedo was accurate before, then I think the math would be like this.

55/85 = .6470588

.6470588 x 21,886 = 14,161.5 miles.

This gives an approximation of the miles traveled by the vehicle, but since the engine was spinning faster, the 21,886 is a more accurate indication of the wear on the engine & trans, although they don't have to work quite as hard because of the mechanical advantage of the 3.91 gears. As far as tires, wheel bearings, brakes & the like, the lower mileage would apply. Somebody correct me if my reasoning is wacko. :violent1:


:burnout:[/QUOTE]

I thought the formula would be something like that! It's only if I re-sale it I wanted a closer mileage without ripping anyone off..or myself..Maybe if I said 16,000 miles.
Thanks.

 

[fishy68]

Jim it illegal here in the states so I can only tell you how it's done, not to do it. If you unscrew your speedo cable from the trans. and hook a drill to it and spin it (backwards I think) it will turn back your odometer.

I believe 64 Cuda is exactly correct in the figures he wrote.

 

[69signetv8]

Jim it illegal here in the states so I can only tell you how it's done, not to do it. If you unscrew your speedo cable from the trans. and hook a drill to it and spin it (backwards I think) it will turn back your odometer.

I believe 64 Cuda is exactly correct in the figures he wrote.

Thanks fishy, I really don't care about the regustered reading due to the motor was change before anyways. I just want to get an idea of "real" mileage that I put on the motor if someone asked what I put on it over the past four years. I think about 15000 miles sounds about right as I was retired and didn't run it in the rain.
Thanks