Ok If i have 79k on my truck and it has always been 5mph fast on the speedo, how many miles do i really have on my truck? thanks in advance.

 

You would have < 79k. Do you know aproximately at how many mph is it +5 mph? What was your stock tires diameter and what is your present tires diameter and and at how many miles did you do the chang?

File

<small>[ October 21, 2002, 01:55 PM: Message edited by: shark_g ]</small>

 

I think I might have figured it out but I'm not 100% sure. I figured 63,200k

 

you wont really figure it out with only "5 mph" off. Is that 5 mph off at 60 mph? Is it off 5 mph at 30 mph too?

Your best bet is use mile markers on a long stretch of freeway (more than 10 miles) and find a percentage your speedo is off. Then multiply your current mileage by the % your speedo is off.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by SSilverado4.82001:
<strong>I think I might have figured it out but I'm not 100% sure. I figured 63,200k</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">63,200k = 63,200,000miles <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> j/k

I think 63,200 would be right if his speedo was off 5mph at 25mph.

It kinda depends on what speed his speedo is off at like shark_g and BigTex posted.

If its off at 55-60mph then you have ~72,000 miles. I'm not a math wiz either though. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

John

 

always 5mph off. i think. I run 295/50 r16s instead of 235/70r16s

 

If your speedometer has been calibrated for 235/75 R 16 tires, replacing them with 295/50 R 16's would result in the speedometer reading high by 8.20%.

thats from the http://www.c5-corvette.com/cgi-bin/tirecalc.cgi

in that case i believe you would have 72522 if its at 79k exactly.

i figured this by multiplying 79k by 8.2% then subtracting that from 79k. i believe my math is correct, if not correct me.
actual milage 100000 mi
indicated with 295/50-16 108197.89 mi
error +8197.89 mi

this is just an example taken from the tirecalc.

 

thanks all

 

I came up with 7.576755830807744% difference (too fast). Still in the ball park of the 8.2%.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by CMNTMXR57:
<strong>I came up with 7.576755830807744% difference (too fast). Still in the ball park of the 8.2%.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">how in the hell did you get that?

you cant use 5mph b/c there is only one speed where it could be 5mph, as speed increases/decreases the difference also increase/decreases.
so it might be 5mph off at 30mph but 10 at 60mph and so on... it just varies.... if you put the 235/75-16 in for tire A and 295/50-16 for tire B. in the link i posted and select to compare tire A and B it will show you the differences at different miles per hour and milage.