gps for use as speedometer

longtimelurkersam

I use the speedo on my Sat Nav almost pretty exclusively. On my old Transit the speedo was so variable it was a joke. On my TT and the T4 van the speedo is pretty accurate compared to the Sat Nav, but the Sat Nav has all the other warning things for accident blackspots etc plus it is on the screen in my line of sight and requires hardly any adjustment in my field of vision when driving.

i only look at the instrument panel when a light flashes up or a warning sound is heard.

McCoy

Can't you just glance at the speedometer your car came with like normal people do rather than introduce a technological solution to a problem that doesn't really exist?

EdGasket

A car's speedometer is innacurate and will vary as your tyres wear. Think about it!

andover_2

Thanks very much for replies.

Arcon5

I think you missed the first part of my post “It is basically just to give me a "line of sight" indication of my speed, so I dont have to take my eyes off the road too often.” I will not rely on it “exclusively”; I will verify its reliability by checking with the in-car speedo from time to time.
That is what I meant by saying I would use it in “conjunction”.

Jaydeeuk1

Thanks for the link to ebay. I had not heard of the HUD box before. I will certainly check it out.

DUTR

The digital display will be on the dashboard so will be quicker to read because it is in line of sight.

Amcg100

This may surprise you but I am actually more worried about not keeping up with other road users in a 30 or 40 mile an hour zone. My in-car speedo tells me I am at the limit but other drivers are tail-gating me.

What you are suggesting is exactly what I am looking for. I want a device that will ping and give an audible (and visible) warning when I am exceeding the speed limit. I don’t want to exceed the speed limit but I do want to keep up with the other traffic.

pompeyrich

Sounds just like what I need. Wish I had a smart phone. Thanks for the info.


Longtimelurkersam

Where you are now is exactly where I want to be.

Hopefully, someone here can name me a sat-nav that has the capabilities that you describe.

Thanks for all your replies.

andover_2

McCoy wrote: »

Can't you just glance at the speedometer your car came with like normal people do rather than introduce a technological solution to a problem that doesn't really exist?

I glance at the in-car speedo and it tells me I am doing 30 in a 30 mile an hour zone. Other cars are tail-gating me and some others are overtaking at the first opportunity. You say this is a problem that doesn't really exist?

I say it does. I say the in-car speedo is under-reading my speed and I intend to do something about it.

Thanks for your help.

londonTiger

the trick is to be able to keep a constant speed. That way you don't need to check your speedo every few seconds. Get to 30mph, and hold. Ususally there's a point in the gas peddle where you apply just enough to maintain the speed. Once you figured what that point is - the rest is easy.
GPS speedos are handy for checking that your in car speedo is correct - but I don't think it's practical to use one ever yday as your regular speedo.

reeac

EdGasket wrote: »

A car's speedometer is innacurate and will vary as your tyres wear. Think about it!

That's a very small effect - around 1-2% i.e. 0.5 mph. at 30 mph.

I got a GPS a few months ago and find that it reads about 1 mph. lower than the car speedo. at 30 mph. but more importantly from a safety viewpoint it takes significantly longer to read its speed display than for the speedo due to it's small digits as compared with a generously sized analogue pointer.

wba31

andover wrote: »

Hopefully, someone here can name me a sat-nav that has the capabilities that you describe.

All sat navs will do it, to name one, ive had a tomtom that did it.

But deep down i question your need to spend on a sat nav just to keep up with traffic. If i wanna do quicker than 30 in a 30 i may be on your !!!! if you're doing 28mph according to sat nav or 32 mph according to speedo. I bet on some 30mph you could drive at 40 and still have someone behind wanting to go quicker.

my opinion is you should just drive at a speed comfortable to you, and if someone wants to sit on your !!!! or overtake just ignore them, you can only account for your driving. i have been an impatient driver but ive never lost patience with someone for doing 28 in a 30, or 37 in a 40, its the 20s in a 30 (when clear) or 30 in a 40 that frustrates me. However thats my own problem, the driver that is holding me up is entitled to drive at a speed they deem safe, remember its a speed limit not a speed target...

McCoy

andover wrote: »

I glance at the in-car speedo and it tells me I am doing 30 in a 30 mile an hour zone. Other cars are tail-gating me and some others are overtaking at the first opportunity. You say this is a problem that doesn't really exist?

I say it's rather glaringly obvious that this is a problem with impatient drivers behind you who wish to break the speed limit.

No speedometer in the world that you fit in your car is going to prevent the situation you describe here.

andover wrote: »

I say it does. I say the in-car speedo is under-reading my speed and I intend to do something about it.

Again, I say that the type of driver tailgating you and overtaking in a 30 zone is not going to be prevented from doing this by you going to the expense and trouble of installing a super-duper accurate speedometer in your own vehicle.

You truly believe that they're overtaking you if your actual speed is 29.5mph but if your new super duper speedometer means you're travelling at exactly 30mph this type of driver won't tailgate you and try to overtake?

Stop being silly.

andover wrote: »

Thanks for your help.

No problem.

Just to reiterate, no speedometer you purchase will stop idiots like the ones you describe.

Save your money.

richard734

if your concern is the accuracy of your speedo, do a google on Speedo calibration, you need to find a straight measured mile, prefferably the same one teh police use with teh countdown markers, a friend and a stopwatch...
takes about 5 minutes including teh math.