Speed shows 1mph less then cc is set at

Normal.

 

I find if I set the cruise control, say to 80 kmh, it'll mostly sit on that number. If it's a little hilly, speed'll drop and recover, sometimes overshoot a bit. This is on my gen 3 though.

Bottom line: cruise isn't designed to slavishly stick to the set speed, it has a bit of "slop".

 

I have always found with the eCVT, that holding speed in hills is a bit more difficult than on a regular transmission.
But the set speed and reported speed were usually accurate on flatter ground, but not always exactly the same

 

The car doesn't know the terrain or conditions it's driving in; so it errors on the side of caution. I believe the specifications is +/- 2mph, sometimes slower or faster, depending on road grade (up or down steep roadways).

 

And keep in mind that the Speedo is inaccurate as well

 

That's NOT true. Speedometer needs to be within a certain specification!!! I know for a fact that my speedometer is displaying about 1.5mph faster when compared to a satellite GPS across a flat valley floor.
Let say for instance your correct. How would you compensate accuracy for tire wear or different tire manufacturers slightly different tire heights???? Bottom line; if you stick to OEM specification tires, your speedometer should be within OEM specs.

If it really bugs you; just set your CC +1 mph faster to get what you want - It's not rocket science..............

 

I think there’s a rule, speedometers are not allowed to indicate lower than actual speed, and likely another rule, that they should be reasonably accurate. Accordingly manufacturers design speedometers to display slightly higher than actual speed.

 

and when the tires get replaced, different diameters, (or even the diameter change due to wear of the old tyres) will affect the speedo accuracy.

 

federal speedometer rules are a lot more loosey goosey than i would have expected:

CFR-2005-title49-vol5-sec393-79.pdf

 

You're not kidding:



You could be going 55 mph, and speedo reading 50??

There's something else, an international convention IIRC, that speedo can never read lower than actual. Seems sensible.

 

you know the us is not much for international conventions, even before the present admin.
we think we know the answer for everything

 

A ways down the page, the International Agreements section:

Speedometer - Wikipedia

 

unece looks worse than us. i don't see canada

 

Another rule that should be in place,but seems sadly lacking: you should be able to read the speedometer in all conditions. With our 3rd gen, with the pale-green letters off in the centre of the dash, if you're driving with bright sunlight bouncing off wet pavement, good luck with that.

 

yeah, that's a bad setup. our hycam and bolt are much better protected from sun and reflections, having the speedo et al buried deeply behind the steering wheel spokes

 

On my 2021, based on radar signs, my speedo is off by at least 2 mph. The dash always reads 2 mph LESS than the radar. Because of that I set the cc at 2 mph above the posted limit.

Here in Tennessee I have to stay in the right hand lane doing the speed limit not to get run over by most everyone else.