2018 Tacoma Self correcting speedometer?

3” lift with 33”’s. About to setup the speedometer calibrator and my speedometer is dead on? Anyone else heard of this?

 

That's news to me. What are you using to confirm the speed? GPS?

 

Yeah GPS.

 

Yes, it was on my 2nd gen though. Was about 5 mph off with stock tires, put 285/75/16 and speedometer was dead accurate.

 

Was it dead on before the swap?

 

I want to say it was within 1 mph

 

oh wow. Be interesting to see what happened here. I ordered my hypertech to get ready for my own swap, would be nice to send it back.

 

Mine was off 10% after installing 33s. I had to use the Hypertech module to correct it.

 

My 16 TRD OR 6MT on the stock tires registered 2mph faster on the stock tires against the GPS. I put a set of 265/75/16 tires on and it was dead on. When I went to 285/75/16, the speedo showed 2mph slower than the GPS. Now on 35's and it was 3.5mph slower on the speedo compared to the GPS. (This was all at 70mph). I installed the hypertech and used the 265/75/16 as my stock size and the 35's in the new size and my speedo is dead on with GPS at all speeds.

 

All speedos read 3-5% higher (except some early 2000’s Honda’s, they read accurate and they got sued for it). They do that so that they NEVER read slower than you are actually going (with stock tires) due to tire wear, inflation pressure, etc. some read higher than others. Maybe yours was 1mph at 25mph, but no way is it only different by 1mph on 33” tires at highway speeds

 

That's because the SAE standard for speedometer calibration calls for +- 2.5 mph at 55 mph. It is "loos" for a reason... new tread versus worn tread.

 

Must of been it. I was just on the higher side.

 

On my Pro, I put 265/75/16s on it and checked my speedo using my iPhone GPS. It was spot on despite the plus tire size.