Speedometer calibration

Hey what's up everybody. Does anyone here know of an inexpensive way to calibrate the speedometer on a 06 tacoma? I put bigger tires on and it's off like 2-3miles. I know it's not a lot but if there's a cheap way to correct it I'll give it a try. Thanks Joe

 

Yah, I hate having to do the math every time I want to check mileage.

 

Me 2

 

Also in for this...

 

by the way, welcome to TacomaWorld!

 

Thanks !

 

Honestly... no. Requires a programmer behind the gauge cluster.

Always going to run a few hundred bucks

 

In my opinion, there is both speedometer and odometer error. Speedometer error (2-3 mph) on OEM tires as manufacturer attempts to avoid lawsuits (but officer, my speedometer said I was doing 60). Odometer error from change in tire size, either replaced with a different diameter tire, or from wear. Brand new, my speedometer read about 2-3 mph high. Odometer error was almost zero, less than 1%. If you look at tire specs, the P245/75-16 Dunlops are 30.5" diameter, and 683 revolutions/mile with a tread depth of 12/32". 5280 / 683 = 7.73 feet per rotation. 30.5 = 2.5 feet, and 2.5 * 3.1416 (pi) = 7.85 feet travelled for 1 rotation. Using 7.73 is more accurate for a mounted tire with a load, so just using tire diameter to calculate correction is slightly less accurate.

My preference is to use GPS to determine speedometer error, and mile markers for odometer error (use your trip odometer to compare 50 miles). As far as tire wear, compare after 10,000 miles to adjust for the tire now being smaller in diameter, which means less distance travelled per rotation.

 

well, if you are like me and you are mostly concerned with the mpg math there is an app on Googles Play store where you enter your tire size and stuff and it will calculate the percentages and stuff to give you a more accurate mpg... I have downloaded this app but havent even opened it up yet so I have no idea if its any good or not... its called Mileage Tracker if you are interested in trying it out.

 

I Do use my GPS for longer trips but its too much of a pain to open it up and get it going for my commutes during the work week. My trip meters I use one so I know when to change oil and the other one for tire rotations.

 

SPEEDOMETER ISSUES ?
Hypertech speedometer calibrator http://www.hypertech-inc.com/products-speedometer-calibrator.aspx

https://www.rocksolidtoys.com/single-post/2017/08/29/T-Case-Worm-Gear-Install

https://www.tacomaworld.com/threads/transmission-swap-write-up-s.384303/

 

Dakota digital makes one but you'll have to tap into your wires behind the cluster to install. It's around 80 bucks on ebay. I found a place selling the hypertech unit for 180 shipped. Then saw east coast jeeps had an open box special for 160 free shipping. It arrived today. In fact I was just thinking about installing it. Loaded the cd into my laptop. Put in the old tire size and the new 315/70/17 size and programmed it. It just plugs in between the instrument cluster plug and cluster.

 

Hypertechs part number for Tacomas is #730117

 

This video is for a 3rd gen but you get the idea of how it installs behind the cluster. Better than tapping into wires in my opinion. Dash removal is different for 2nd gens.

https://youtu.be/rx44N8sImFU

 

Awesome thanks guys I will look into it.

 

Well, that didn't take too long at all. I think I spent more time looking for the little push pin clasp that goes above the cluster lens than anything. One of them shot out inside and flew off to a new home somewhere in the dash. I suspect it will fall out 8 years from now and I'll wonder what came loose up in there. lol. Guess I'll order a new one, although it holds fine as is, so my OCD doesn't freak out. Another amount of time was spent with me wrapping some thin foam around the black box and little mother board so they didn't rattle against anything up under there. Dash take down and reinstall was pretty simple.

This is the place on ebay I was going to get it, but then I saw a listing for the 160 shipped. 179.00 still isn't a bad deal. Programs tired up to 44" and gear ratios as well. Regular price is 230.00.

http://www.ebay.com/itm/New-Hyperte...17-/253122492403?_trksid=p2141725.m3641.l6368

Looks like my pics got out of order a bit, but meh..

 

Does that also keep the odometer accurate?

 

Yes. The speedo and odometer will be corrected. If the odometer has been off for a while it will still be miles ahead or behind, but from the point of install it will keep an accurate reading. This unit will adjust for different tire sizes as well as different gears, or both.

 

I hooked my hypertech up after programming it for gears and tires and now my speedo and milage won't even read, anyone else have this issue? I pulled that black box out and red it on the computer said it was programed right. I really want this fixed because I'm almost 20 % over on both

 

Same. Haven’t mess with it since(2 weeks ago). Gonna give it another go tomorrow and if it fails, ill be contacting hypertech about it on Monday.