speed ohmeter is fast

Most cities have shops that will calibrate your speedometer. Just do a search for:

"Speedometer Calibration". Many options should pop up. I just did a search for my city of Tucson and had 1/2 dozen shops show up.

Jim

I think 3 to 5 is not uncommon.My MH is slightly fast. Not enough to measure. My PU is about 3 mph fast. Never saw one slower.

Tires are not of correct size for speedo setting in computer. many tire shops have OBD unit to change.

I don't think it's a MH issue. We rent cars several times a year for work and 3-5mph faster than actual speed is pretty common (based on comparison to a couple of GPS that match each other). Sometimes, they match dead on.

Never see one show a lower speed...of course that may be a liability thing. The manufacturer doesn't want the blame if the speedo says 55mph and you get a ticket for doing 60mph.

If the tires are smaller than factory spec. it will read fast. Check if they
are the correct size?

How about the odometer difference compared to 10 miles of mile markers?