Speedometer Question

So just bought a new to me 05 Taco and wanted to do a lift with bigger tires just because so I have been doing all the research I can, pretty much have all my questions answered but one so here it goes.
When you put bigger tires on and the speedometer is off how do you correct it without regearing it. I have seen an inline speed buffer from hypertech that looks like it would do the job but is there any way to reprogram the ECU? I know if you don't it will adversely affect many things mainly your gas mileage and if you have an automatic your shift points. Anybody have any suggestions?

 

bump
anybody?

 

Most people find that the speedometer is more accurate with larger tires than with the stockers. Use your gps to check.

 

still doesn't answer my question though. The computer is looking for so many pulses per mile I know on my chevy it was looking for 8000 or 4000 ppm depending on what set up you had. So when you go bigger you aren't putting out the correct ppm and it will adversely affect your performance so nobody ever worries about it with there taco's? Might be why some of them are getting very poor mileage. Just a thought.

 

I'm not sure about our trucks but I know you can buy a programmer/chip for most trucks that takes care of that. My dad has a chevy with a 6" lift and 35's and a chip and fixed his speedometer that way, so that might be something to look into. Hopefully somebody else can give you a better answer. As for the gas mileage, I just adjust my trip meter miles when I calculate it and use that number to figure out mileage.

 

Regearing won't affect speedometer error, BTW, because the speed sensor is on the halfshaft, downstream of the diff.

 

So the speedo doesn't get data from the same source as ABS?

 

Don't think so I thought Jeep was the only one that does that. Usually you have the abs get its signals from a sensor on each wheel and the speedometer gets its data from a VSS on the transmission or the transfer case. But Toyota could be getting its data from the ABS sensors like the newer jeeps.