Just recently bought a new car ( mazda cx9) whilst driving recntly i had the sat nav going which has curent speed u are travelling , i compared it to he speedometre and it was about 8/9 kph out .. Fortunatly on the low side so speedometre reads 100 but gps reads 92 .. I find it a car so new & technologically advanced could be so far out as ive heard tha gps readings are quite accurate , anybody has ideas on what would be closer to being accurate ?

welly
my truck (isuzu) speedo is LOWER speed than the gps
i always drive to the gps and have never had a fixed camera fine
on my 900 hornet i go as fast as i feel like when ever i want

welly
my truck (isuzu) speedo is LOWER speed than the gps
i always drive to the gps and have never had a fixed camera fine
on my 900 hornet i go as fast as i feel like when ever i want

If i was to start smoking
i think they would be oh i don’t know..
Vanilla flavored i reckon

Well thats sorted tht out then .. LMFAO !

Nice to know u air on the side of caution : /

My Tom Tom records a lower speed than my speedo.

Just recently bought a new car ( mazda cx9) whilst driving recntly i had the sat nav going which has curent speed u are travelling , i compared it to he speedometre and it was about 8/9 kph out .. Fortunatly on the low side so speedometre reads 100 but gps reads 92 .. I find it a car so new & technologically advanced could be so far out as ive heard tha gps readings are quite accurate , anybody has ideas on what would be closer to being accurate ?

Trust your GPS. There are too many variables (tyre pressure etc) with your speedo. If you ever go through a radar where the speed is displayed it will usually match the GPS.

Cabbage, did you need a GPS to get out to Kilcoy or just follow the smoke signals?

The GPS should be spot on, provided you are travelling at a constant speed – highway cruising.

Just to be sure, also fire up the gps in your phone as a third reference.

Welly, take it back to the dealer and tell them it’s significantly wrong. They should have some means of verifying it and fixing it.

Cabbage, did you need a GPS to get out to Kilcoy or just follow the smoke signals?

Have you come here to play Jesus, with the leopards in your head

I nearly ended up stuck there. Couldn’t find a petrol station so went to Woodford. Couldn’t find one there either. Had enough fuel to get to Caboolture by about 10km.

Was very relieved to find a servo a few k’s out of Woodford.

8 or 9 km/h off your actual speed at an indicated 100km/h is within manufacturing tolerances. Don’t bother taking back to the dealer, they won’t do a thing about it.
They’ll only help you out if its under reading.

ADR regulations state cars sold here cannot under read your actual speed.
They are allowed to over read by up to 10% though

yep, acceptable error rate is between 5 and 10%
allows for all sorts of variables – hill, wind, tyre pressure, surge etc.
If you are doing your speedo speed you will always be below the road speed limit.
coppers’ speed traps are always set above the posted speed limit by a similar amount to allow for similar variables.

Yep my Mazda 3 is the same. Noticed it first on the drive down to Melbourne where they have the speed traveling signs on the bridges. Then checked on the GPS and those two matched while my speedo showed about 8 – 9% lower.

Now I know that 120 on the speedo is about 109 kmph.

I think the majority of cars are like this though because I sit on 110 on the speedo i’ll flow with traffic but if i move to 120 – 125 I zoom passed everyone even though i’m doing the speed limit.

My new SV6 also reads about 3 kmph lower than my phone GPS. I first noticed it when travelling through various roadworks where they have a “your speed” sign. Always a slower reading than the car.

Ok so the gps is more accurate , i wonder if the car speedo can be corrected .. Sort of dialed in so to soeak as arent most of the electronic nowadays !

Ok so the gps is more accurate , i wonder if the car speedo can be corrected .. Sort of dialed in so to soeak as arent most of the electronic nowadays !

They might be able to get it closer but it will never be perfect – They’re too many variables such as tyre pressure, road conditions and wind that will effect the reading.

Even 2 million dollar supercars don’t have accurate speedos – watch any high speed run in a supercar and they will fit an external device to measure the speed rather than rely on the cars own reading.

Beings as my sat nav is in middle of dash an the speed is quite small in the lower corner of that, just means im taking my eyes away from the road more than im comfortable with at times when relying on the gps .. Even though i now know that the speedo is out would rather use that and have it correct if at all posible .

Beings as my sat nav is in middle of dash an the speed is quite small in the lower corner of that, just means im taking my eyes away from the road more than im comfortable with at times when relying on the gps .. Even though i now know that the speedo is out would rather use that and have it correct if at all posible .

If it concerns you that much just work out how much it is out by and adjust accordingly. That’s what i do.

I know 120 is about 110 and i know 85 – 87 is about 80 – so in an 80 zone I just sit on 90 and am probably traveling 2 or 3 kms over the speed limit which is fine.

If i go through a speed camera, I drop it back to 80 and i know i’m well and truly safe.

most car speedos are actually calibrated to show a little higher than what they actually are. Amount depends on the type of car as well. You will find in most high performance/ supercars that they are actually pretty spot to the actual speed.
gps is much more accuracte but also slightly delayed by a couple of secs.

then tolerance per state with police is different, VIC is deadly, NSW approx 8-10%