My 2007 h2
#311
09-05-2019, 06:47 PM
You didn't lose fuel economy, your miles are not properly recorded on the odometer.
Effect of tire size on odometer readings
Assumption:
- The odometer “calculates” the distance based on the number of revolutions for the tire.
- The diameter of a bus tire is 36 Inches.
- Tire treads are worn evenly over the entire surface of the road. Therefore; 1/8” tread wear amounts to 2/8” reduction in diameter.
Observations:
- The revolution of a tire is equivalent to the circumference of the tire.
Fact:
- The Circumference of the tire is equal to PI times the diameter.
- 1 Mile = 5280 feet.
Calculations:
- The Circumference of a 36 inch tire is PI * 36 = 113.1 Inches or 9.42 feet
- The Circumference of a 35 6/8” inch tire is PI * 35.75 = 112.3 inches or 9.36 feet
- Calculate the revolutions required to travel 1 mile (5280 feet). 5280 / 9.42 = 560.51 revolutions
Intermediate Conclusion:
- For every 560.51 revolutions of the tire, the odometer will register 1 mile.
Further Calculations:
- In 560.51 revolutions, a 35 6/8” tire will travel… 560.51 * 9.36 or 5246.37 feet.
- For each 560.51 revolutions, the odometer will increment by 1 mile even though the vehicle has only traveled 5246 feet. Therefore, a vehicle with tread wear will report more miles driven by the odometer.
- The difference in distance is 33.63 feet for each mile driven. Actually traveling 157 miles will cause the odometer to be off by 1 mile.
- The percentage of error is… (1 - 5246.37 / 5280) * 100% = 0.64%
Conclusions:
- 1/8” tread wear on a 36-inch tire reduces the circumference by 0.8 inches.
- Over the length of 1 mile, this adds up to 33.6 feet.
- After “actually” traveling 157 miles, the odometer will be “off” by 1 mile. It will read 158 miles.
- Smaller diameter tires will effect odometer reading more than larger tires.
#312
09-06-2019, 12:04 PM
Actually my speedometer and odometer are correct within factory limitations anyways. Tire wear is a fact of life that does alter things some but I've corrected the baseline on mine. I have both a Tech2 and EFILive and with either you can change the tire size fitted to correct the speedometer as well as the odometer. On the Tech2 it is oddly under the ABS system functions. I changed mine with EFILive since I am running a custom tune and even verified with GPS before and after that things were corrected after I changed it....
Regardless - if you do put on tires that are not a stock size then your speedometer and odometer will no longer be correct unless the fitted tire size is corrected in the PCM using a Tech2, EFILive, HP Tuners, or some other tuner that can modify that. Any good tire shop who puts on tires that are not a stock size "should" let people know that but most do not care and just are interested in selling a set of tires.
Regardless - if you do put on tires that are not a stock size then your speedometer and odometer will no longer be correct unless the fitted tire size is corrected in the PCM using a Tech2, EFILive, HP Tuners, or some other tuner that can modify that. Any good tire shop who puts on tires that are not a stock size "should" let people know that but most do not care and just are interested in selling a set of tires.
Last edited by MixManSC; 09-06-2019 at 12:07 PM.
#313
09-06-2019, 03:30 PM
Just got my handles and I’m very happy with the quality and finish. I put it on to see how it was going to look and I think all chrome is a bit much so I will have the buckets powder coated and cleared. It’s a heavy stout assembly and it came with SS pins and eclips to hold the handle on. You will need to reuse the spring pivot assembly off your old handle.
Last edited by maxjeep; 09-06-2019 at 03:32 PM.
#316
09-06-2019, 06:38 PM
Rolling resistance increase is a factor, however not as much as the increase in diameter.
Here's an example:
#317
09-06-2019, 07:10 PM
Just got my handles and I’m very happy with the quality and finish. I put it on to see how it was going to look and I think all chrome is a bit much so I will have the buckets powder coated and cleared. It’s a heavy stout assembly and it came with SS pins and eclips to hold the handle on. You will need to reuse the spring pivot assembly off your old handle.
#319
09-06-2019, 07:48 PM
I think so too.. thought about doing the handles also but like you said everything chrome has some black on it.
#320
09-09-2019, 04:27 PM
I need a little help members. Does anyone know what door panel clips are needed? I would also like to replace whatever is on both ends of the latch/lock rod. I would like to have everything here before I start the handles. Thanks for your help!