Speedometer

[caymann]

Why do some coaches have a max of 85mph in their speedometer whereas others i have seen go to 120 mph? What determines this?

["007"]

I don't think the speedometer has much to do with speed whether 85 or 120 its your tire MFG's warning do not drive over 75 mph on your tires for extended period.

[wa8yxm]

A lot depends on who made the coach and a few other things.. Speedometers used to go up to 120 on most all vehicles.. But a few went higher (And did too).

Many coaches, these days, are governed at like 80 mph, over 80 (or to be more accurate 8x where x can be any interger, zero included) the ECC cuts off fuel flow or otherwise "Throttles down" the engine (I have hit 82, full idle (Foot not touching pedal) down a slight grade, with a bit of tail wind (90-100 mph) and the driver info display said "Excessive Veh Speed" or something like that.. Had I had my foot on pedal the ECM (ECC ECM, same thing) would have throttled me bac.

So, if the rig's top speed is 80.. Why make the meter go to 120?

[Luv2go]

On Ford F53 chassis (at least the 2008), speed is governed to 75MPH. Speedo reads to 100 or so. I've heard that many Workhorse coaches are governed to 80, as wa8yxm mentioned.

Stewart

[paz]

Workhorse also governs the speed to 75, but the speedometer goes to 100.

I don't know of many motorhomes that could go 120. Some motorhome manufacturers may use an off-the-shelf speedometer, and that speedometer happens to go to 120.

FWIW, Michelin XRV tires are only rated for 75 mph sustained speed. I don't know about other types of Michelin tires or about other brands.