DanJHartman

I own an 05 SS/SC and i was wondering if anybody else ever has problems with accurate speedometer readings.
heres my issue, every time i pass one of those police radars (the type that display your speed) it always says im going at least 5 mph slower than what my own speedometer says. i know that with any of my other cars it has been dead accutate EVERY time. Also my GF has an 06 SS sedan, and once when messing around cruising at the EXACT same speed (side by side) i asked her how fast she was going (talking on a cell phone like an *$$hole)....anyway i was doing 75, and she was doing 68...thats a big difference and it kinda annoys me,
Also, wouldnt that make the car rack up miles much faster??...cus i know that the older model cars mileage guages were tied into the speedometer but im not too sure about the cobalt setup
Any imput???

Jmc007

Do you get your tire changed with another brand / size or running winter tires ?

DanJHartman

nope im running on the complete stock wheel setup...

ptparker

those police things have a really bad habit of falling out of calibration. Also if there is any other traffic on the road, either with you or oncoming, it will mess them up further. They are kind of fun to play with though...

DanJHartman

lol yeah cops around me have nothing better to do....so they all sit on sideroads and pull people over using those things so theres no mistaking your car speed with another here
next time ur cruising with sombody that you know call em up and check your speed with theirs..
maybe this explains why it always feels like im going so slow until i look down at the speedometer

memphisr24

Yeah, when I'm not moving, my needle is at about 1 mph. I wonder if my guage is wrong too. Iknow around town, which is 25, I usually do around 27-29 and every single time there is someone on my ass. Hmm.....

Cobalt443

when i had my base cobalt it shut off at 105....well i was cruisin' down 287 (late at night no one really on the road) and i got pulled over doing 113.....the cop happened to be an ex of my sisters so he let me go...but i find a pretty decent difference from 105 to 113 (and i wasn't going downhill)

memphisr24

This could explain how some of the 2.2 cobalts are getting different top speeds. Some are only getting to 105 and some are claiming 120.

Dark-Fx

I loose about 3% on my speedo. When it says I'm going 81-82, I'm actually going 79. tires I'm running are only supposed to be about .5% quicker then stock, so it's actually about 2.5% off.

I think they overrate the speed because people that drive our cars have a tendency to go too fast anyway. Stupid government regulations.

trent_ky

I dont know ive only had my car for a week but I have noticed that people seem to ride my ass even when im going 5-10 over...

alleycat58

I saw one on one of the more deserted interstates around here, on about a mile straight stretch going downhill left over from construction season (hello, open invitation to "play" with the coppers' speed sign)...I gunned it, speedo read 105ish, sign said 69mph...they're not the worlds' most accurate devices.

The dealership can calibrate your speedo, and it really should be under warranty as well, just tell them it's off, and about testing it with yours and your girlfriends' cars driving side by side and reading different speeds.

Badmunky

Well the base 2.2 cars are set at a top speed of 109. the SS however (Correct me if im wrong) donst have a top speed limiter.
And the averag speedo is off by 3% at 80mph according to an artical in car and driver a few years ago.

Later

alleycat58

I do believe the N/A SS's have a speed limiter, the S/Cs are drag limited.

Cobalt_Supercharged

You can also test it on the highway. Get a stop watch and set the cruise control to 60mph. Time it between mile markers. At 60 it should take it exactly 1 minute from marker to marker. 75 mph should take 48 secs if my math is correct.

Brian MP5T

**** That Calculation ****.

Get a **** GPS and check it properly.

mcphatty

^^^ agreed.

i find that my speedo is about 3% off according to my GPS

DanJHartman

^^ true...i have to try that

Dark-Fx

Yeah, I forgot to mention that I tested it with my GPS. GPS is supposed to be incredibly accurate when calculating speed as opposed to your actual location, because the error in location will be almost the exact same every time it's calculated.

DanJHartman

so is your car displaying your speed to be too slow or too fast?

mcphatty

the speedo displays too slow. if your speedo says 80, you're actually going about 78,77

Badmunky

From what I was able to find the SS N/A is limited to 130mph and the SS S/C is drag limited to 145mph

Later

Brian MP5T

The GPS is the only way to really get a true idea of where your speedo is, it will vary from model to model and even from car to car. A GPS is a very common item now that you can get for under $100.00 for a cheap one. It's a neet CAR TOY.

EuteR

You know... Just yesterday I was driving beside a new civic with a digital dash. The speed on the dash read 52 KM/H and my speedo was at 60 KM/H. I never thought toooo much of it. But now this thread pops up, and makes me wonder.

Doc

I have one I run with, it connects to my watch. My speedo is accurate according to the GPS I have. My watch is an Ironman, I think the whole setup cost me $250. There is a pic in the gallery with the GPS unit on my arm. I used it when I ran a half-marathon.

mkulrey13

iTrader: (39)

Well it could be a good thing. Say speed limit is 55 and your going 75 which is crimal speeding i believe 20+ Over. But when ya get pulled over your clocked in at 71-73 which is under 20. lol bring it in and get it checked out.