GPS Insight Blog

That seems like I’m stating the obvious, but GPS does not equal accurate odometer readings.

Many of our competitors don’t even give you that information — just the # of miles driven.

Here at GPS Insight, we have recently released a VERY ACCURATE odometer calibration mechanism to ensure that no matter what type of vehicle or GPS Tracking device you use, your odometer readings will be about 99.8% accurate.  This is a big improvement from the typical 98% “best” we see with competitors.

If your vehicle drives 10,000 miles a quarter, we may be off 20 miles.  They may be off 200!  Even so, that’s not going to cause an engine blowout, but if you are billing or charging departments based on accurate mileage, GPS Insight will help you avoid the inevitable questions once GPS mileages are scrutinized.

A year and a half ago, we allowed our customers to enter multiple historical corrections, which is much better than the single “offset” which most companies provide.

Now we have improved this in 2 ways:

• Offsets (corrections) are “spread out” historically to avoid spikes in mileage
• Corrections are used going forward as a calibration to more accurately depict odometer readings so odometer corrections are much less necessary & can be done once or twice a year, vs. once or twice a month.

This was surprisingly a HUGE amount of work, which explains why none of the other providers we’ve seen have ever bothered to fix this fundamental flaw in GPS tracking devices.

Here’s why they’re not accurate, by the way:

GPS Tracking devices typically pull mileage from “GPS Interpolation” — since they know where a vehicle is at any point, they can compute the mileage between points.  Our GPS-based odometer calculations take place 4 times a second, but they are still slightly off — typically 1-3% lower than reality.  This is also because we are adding to mileage when a vehicle is in reverse, even though the odometer isn’t incrementing.

Some devices, such as our LD-3500, pull odometer readings as a function of data from the engine’s computer — but not the odometer reading itself.  Again, this is typically 1-2% off, overstating mileage.

There are all sorts of nightmarish billing and leasing problems which we’ve heard about from our customers when odometer readings aren’t 100% (or at least 99.8%) within GPS Insight, so we made these changes.  After a few weeks since the newest, now “calibrated” adjustment, my vehicle is within 1 mile of accuracy, which is partly due to the rounding on this report.  I probably won’t need to adjust the odometer again all year as a result of these changes — here is what GPS Insight thinks my odometer is for each device, when my actual odometer reading is 35,482.  By the way, some people claim GPS is MORE accurate, since tire pressure & size, as well as tire slippage can throw off an odometer.  Good luck proving that one though.  The reality is everyone goes by the odometer reading & we need to ensure we’re as close to that as possible.

Show historical odometer correction history:

Here is the new interface for viewing and editing historical odometer corrections, along with a really cool new graphing mechanism we’ll be using within the site going forward for other things:

So, to summarize, just know that GPS Insight is working very hard to ensure your data is as accurate as humanly possible, given technical limitations which exist with GPS Tracking devices.  By the way, the good news is that Heavy Duty Vehicles (J-1939/1708) using our 3500-HD have always had 100% accurate odometer readings since that is the only device available which gets real odometer readings from the engine.

Enough about Odometer Readings — I’m very glad this project is over — very important but not the most exciting thing in the world…

On to more interesting things now (like user-definable categories & attributes for vehicles, drivers, landmarks, users, stops, and trips)!

Rob.

Tags: gps fleet tracking, GPS Tracking, gps vehicle tracking, odometer improvements, odometer readings