2MPH delta between speedometer and cruise control…..

[PhoenixM3]

Ok, I set my cruise at 70 mph and speedometer reads 72 mph. Speedometer is accurate when compared to Uniden R7 speed reading. I find it odd that the cruise is this far off actual vehicle speed.

Sponsored

 

[Bearded_Dragon]

I thought this when I bought my Wrangler, but I realized the speedometer is off-center. If I lean over the needle is exactly lined up at whatever I set it to.

 

[Reinen]

If you're in a hilly area it's not that uncommon for CC or ACC to be +/- 3 MPH off as it deals with the terrain. They should match up on flat ground though.

 

[jeepdabest]

People complain about the Jeep being unsafe with clutch fires and death wobble, etc. However, NO ONE tests more vehicles to insure your safety than Jeep. NOBODY.

 

[Deleted member 59498]

Is the hairnet required equipment for the test dummy?

 

[jeepdabest]

Is the hairnet required equipment for the test dummy?

It holds in fluids to measure them from the deceased.

 

[aldo98229]

My Sahara too came from the factory with the speedometer overstating my speed by 1.5 MPH, measured against those electronic speed readers on the side of the road.

I was able to recalibrate my speedometer by setting my tire size 1/2-inch smaller than actual.

It is now spot-on.

 

[PhoenixM3]

I thought this when I bought my Wrangler, but I realized the speedometer is off-center. If I lean over the needle is exactly lined up at whatever I set it to.

Parallax error in reading the speedometer is not the issue. I set the cruise for 70 and get a bonus 2 mph.

 

[PhoenixM3]

My Sahara too came from the factory with the speedometer overstating my speed by 1.5 MPH, measured against those electronic speed readers on the side of the road.

I was able to recalibrate my speedometer by setting my tire size 1/2-inch smaller than actual.

It is now spot-on.

Speedometer is dead on.

 

[PhoenixM3]

If you're in a hilly area it's not that uncommon for CC or ACC to be +/- 3 MPH off as it deals with the terrain. They should match up on flat ground though.

This was on a flat section of I70.

 

[Dyolfknip74]

I thought this when I bought my Wrangler, but I realized the speedometer is off-center. If I lean over the needle is exactly lined up at whatever I set it to.

I imagine they're talking about the digital one in the center as opposed to the analog one. I don't even use the analog one.

 

[BuyHold]

Parallax error in reading the speedometer is not the issue. I set the cruise for 70 and get a bonus 2 mph.

When you are dead stop the speedo says 2mph?

Or is the error a percentage of actual (e.g. reading is +2.857% from actual -> 2mph at 70, 1 mph at 35, 0mph at 0... 4mph at 140?)

 

[Sidewalk]

My cruise holds the set speed right dead on (my speedometer is the most accurate speedo I've owned so far too).

If I set the cruise for 65, the radar on the side of the road says 65, GPS says 65, and speedometer says 65.

 

[Shibadog]

I’d not be surprised if the factory “fudges” a little on the side (reading a tad higher than actual) I believe their is even an industry standard that allows like 5% error-which would be right where you are. (Well actually you’re closer than that). I know when I went to 285’s on my Sport the Speedo is still very close-70 indicated is 72 actual per gps. Obviously with much small tires it would have been off the other way.

 

[PhoenixM3]

When you are dead stop the speedo says 2mph?

Or is the error a percentage of actual (e.g. reading is +2.857% from actual -> 2mph at 70, 1 mph at 35, 0mph at 0... 4mph at 140?)

I’ll double check but believe it reads zero while stopped. Also, doubt the Jeep would hit 140 falling from a plane…. Speedometer and cruise setting moot at that point.

Sponsored