Maybe ChevyMgr could shed a bit more light here, not sure if it's applicalbe to the HHR........

under bulliten 83-83-16..........

There is no problem if you are within these parameters.........

• 20 mph..................+/- 4
• 45 mph..................+/- 3
• 65 mph..................+/- 2

 

Your speed synchronization problem my be related to any changes you made with your wheels. Since the LS comes with 16", the LT with 16 & 17" and the SS with 18" wheels, maybe the fault is with this discrepancy. On my VW Passat, I went from 15" 195/65 wheels/tires to 17" 235/45 wheels/tires and now have to set the speedometer to @ 58 mph to travel at 55 mph. By the way, my average gas mileage also went down, I was getting 32+ and am now getting 30+. This with a 1.8L Turbo, 5-speed.

 

According to my GPS my HHR at 70 is 2mph slow. I find this with all GM vehicles I have driven in the past 10 years. I bet all vehicles are on the slow side to protect them from being sued by someone who got a speeding ticket. My Goldwing was almost 5 mph slow.

 

Geez, jx3.....you're going back pretty far with that bulletin #. If I remember correctly, that sequence of numbers expired about 10 years ago. Isn't there anything newer than that for the more technically accurate vehicles???

 

My HHR reads about two mph higher than my GPS reads. I figure that I'm safe from a ticket when I'm driving the posted limit. I have another car that the speedometer reads 5 miles lower than the the GPS plus the odometer is off by about 5%. So my car that shows 140,000 miles really has 147,000 miles on the clock. It still runs good.

 

Snoopy, how is the average joe suppose to know dates in relation to sequence?

As I noted first in the post........maybe ChevyMgr could shed some light on it.

 

Good point. I assumed (wrong thing to do) you did a simple search on it. Or that you had already researched the item. In either case, the effective date is provided with the #. So, just now, I went to Google to comfirm. First "hit" gives the September, 98' date. My memory is off slightly (I still use the Ol' Guy excuse) .

But I wasn't criticizing. I, as I mentioned, thought you were researching the item. Thought maybe there is a more recent bulletin/tsb regarding this, and was asking for that.

 

Your right Snoopy, actually the TSB I found says to discard the one I posted earlier, wasn't paying enough attention to the number I grabbed.

How about this one, posted May of 08 is where the +/- differences came from...........

#08-08-49-011.....how relevant is this one to the HHR?

 

Wow... + or - 4 MPH @ 20 MPH?

My GPS confirmed that it was between 1 or 2 MPH at all speeds including highway speeds.

My S-10 was right on! Oh well. (And so is my father's STS...haha).
I guess this is okay.

 

Look at it this way: just your tires wearing out (1/4" on the radius) over time will put your speedo out about 2%. There are all kinds of sources for error.

Yves