Toyota Smarter than us or Stupid?

I have read numerous posts from folks regarding speedometer issues . The feedback from TW members seems to be that Toyota has an allowable amount of error ~10% and if is with in the margin of error, they will not replace the equipment. The trend that I have noticed, more often than not, is where the speed is reading higher than the vehicle is actually traveling.

What are the benefits to this and to whom?

1. With speeds higher than actually traveled miles will be clocking faster than the vehicle actually travels thus your warranty will expire sooner than it should. Benefited party – Toyota

2. If you put on plus size wheels and tires you may be able to correct some of that error. For example, if you have a two mile per hour error and go to a 17 inch wheel you should be able to correct it to zero. If you go to an 18 inch wheel you may clock miles slower than actual and thus your warranty will last potentially longer than the actual miles driven. Benefited party – Owner

So my question is do you think Toyota assumes owners will be putting on larger size wheels and tires on their Tacoma's and as a result factors this in and put's in speedometers running with this error?

 

wheel size doesnt affect the distance traveled(or mph) the larger tires do. Its actually about 5% error from the factory to my knowledge.

I have larger tires and now my speedo is slightly slow- I win!
When it reads fast, you cant get a ticket as easily either. You're going about 3-4 mph slower than it reads on the highway- I win!

 

There are a few ways to fix the speedo errors-mainly Healers and Different size tires if that lil bit of error bothers you that much

Plus I think you'll find most dealerships will not deny you necessary/warranted services at 36001 miles. Most will work with you for a reasonable amount of time...Items that need warrantee coverage are pretty obvious.

The speedo tolerances are set the way they are for exactly the reason you mentioned. They used to be unable to make speedos more precise- so they accepted the tolerance and moved on. Now-They still build to that tolerance but it's because of the fact it's so easy to modify cars-that anyone can make the speedo do whatever they want.

 

Kinda hadn't thought about it like that...IDK but I think there were 2 tires sizes for my 2008 Access Cab (245 and 265). I guess in that case it is kinda planned...

 

Yeah, some packages come with different tire sizes but on the 2nd gen Tacoma the 245's and 265's are on a different aspect ratio, and even wheel size. That makes them almost the same exact size:
It's 245/75/16 (SR5 4x4 and prerunner)- 30.5" tall
and 265/70/16 (OR package)- 30.6" tall
and 265/65/17 (sport package)- 30.6" tall
these are basically the same size. Just that little .1" can vary between tire manufacturers very easily.

 

None of the above ...

The FSM spec allowable variance is on the order of 5%.

I don't know of a brand / manufacturer with tighter tolerances on speedometer readings.

 

Way back in the old days (like with my 68 Charger) you could go to the dealer, give them your rear end ratio and tire size, they'd check a chart and give you a speedometer pinion that would make the speedo correct.

I was on a Corolla forum a few years back and asked if something like that could be done with newer Toyotas. Nobody could say yes or no. The speedo on our trucks is electronic, and driven by a reluctance sensor screwed into the tranny. You'd think they'd make different sensors to correct problems like this, but I can't find anyone that does.

 

First off....I don't think there is any problems with the speedometers.

If you owned a Scangauge and a GPS, you'd know this already.

My 2007 truck reads 2mph fast on the dash speedometer.
The Scangauge takes readings directly from the computer (ECU) which matches the GPS (which is 2mph slower than it reads on the dash speedometer). I've also done a quick mile check, and found my truck to be
.02 of a mile off.

Since the ECU is the GOD of all tacoma data - than that only means the needle on the speedometer isn't calibrated properly to the numbers on the dash panel. It doesn't mean anything other than a visual concept to the driver.

Get a Scangauge II and you can see the actual readings yourself.

 

^^
Janster's wicked smart...

 

WOW good job..

 

I have 20" wheels & when I go by a radar on the side of the road that shows your speed. My speedometer said I was doing 35, but the radar said 31. I have noticed a 3-4 mph less than the speedometer shows whenever I pass one of these radar trailers. I guess it keeps me from speeding by being less.