Every vendor has a payback figure. None of them will show you where it came from. Here's how to build one you can actually defend, using published data and four numbers you already have.
We looked. There is no government, academic or industry-association source that publishes a measured telematics payback period. Every "ROI in 60 days" and "pays for itself in three months" figure we could trace led back to a vendor's own marketing.
That doesn't mean the return isn't real. It means the honest way to estimate it is from first principles, using your fleet's numbers and published rates, rather than from a claim nobody stands behind.
**1. Your idle hours per vehicle per day.** You probably don't know this precisely. Estimate, then verify — almost every operator underestimates, often by half.
**2. Your burn rate at idle.** Argonne National Laboratory's measured figures by class:
| Vehicle | Class | Fuel | Idle, no load | Idle, with load |
|---|---|---|---|---|
| Full-size sedan | 1 | Gas | 0.39 gal/hr | 0.59 gal/hr |
| Delivery truck | 5 | Diesel | 0.84 gal/hr | 1.11 gal/hr |
| Medium heavy truck | 6–7 | Diesel | 0.44 gal/hr | — |
| Tow truck | 6 | Diesel | 0.59 gal/hr | 1.14 gal/hr |
| Bucket truck | 8 | Diesel | 0.90 gal/hr | 1.50 gal/hr |
| Tractor-semitrailer | 8 | Diesel | 0.64 gal/hr | 1.15 gal/hr |
Use the "with load" column if your vehicles run PTO, hydraulics, lift gates, refrigeration or heavy HVAC while stationary. For service and utility fleets that is the realistic figure.
**3. Current diesel.** As of the week ending 3 August 2026, the EIA Lower Atlantic average — the region covering Georgia and the Carolinas — was **$5.168 a gallon**. Check the current figure rather than reusing ours; it moved 55 cents in the four preceding weeks.
**4. Disputed or unverifiable billable hours.** If you bill hourly, this is often larger than the fuel line and nobody includes it.
Eight service trucks with PTO. Assume three idle hours a day each, 250 working days.
Now apply a realistic recovery rate, not a hopeful one.
The best independent evidence available is a University of California, Davis meta-analysis pooling **17 studies** of onboard eco-driving feedback. It found an average fuel economy improvement of **6.6%**, with a 95% confidence interval of **4.9% to 8.3%**.
Applied to the whole fuel bill rather than just idle, that is a modest single-digit number. Applied specifically to eliminating *unnecessary* idle — which is where the concentrated waste sits — fleets typically do better, because you are removing a discrete behaviour rather than nudging an average.
Say you cut half the idle. That's roughly **$17,000 a year** on eight trucks, from one line item, before you count anything else.
Compare that against eight installs plus eight subscriptions and you have a defensible first-year figure specific to you.
The same UC Davis analysis found something more important than the headline number: the effect **declines by about 0.1% per day** as drivers habituate.
Telematics is not a set-and-forget saving. Left alone, the fuel benefit erodes month over month.
The fleets that hold their savings are the ones where somebody reviews idle and driver reports weekly, compares drivers against each other, and does something about the outliers. That is a management commitment, not a hardware purchase, and it should be in your ROI assumptions.
If nobody in your business is going to own that, discount your estimate accordingly — or don't buy yet.
**Verified hours.** Immediate and permanent, and it doesn't decay, because it isn't behavioural. Either the vehicle was there at 9:04 or it wasn't.
**Maintenance scheduling.** ATRI put 2025 industry-average operating cost at **$2.336 per mile**, with repair and maintenance up **8.6%** year over year. Moving even a portion of maintenance from unplanned roadside to planned shop work is worth real money, and voltage trend data will show you a failing battery before it strands a truck.
**Claims exposure.** Harder to price and potentially the largest. ATRI found the mean time from crash to verdict was **1,319 days**, and that a 1% increase in that interval correlated with roughly **$3 million larger awards**. The US Chamber Institute for Legal Reform puts the median nuclear verdict at **$21 million** for 2013–2022, with six states — **Georgia among them** — producing about 61% of them.
You cannot put a first-year number on that. You can recognise that evidence you have is worth more than evidence you assemble three years later.
**Insurance discount, if any.** Real but smaller than advertised. GEICO announced up to 10% for new commercial policyholders sharing Motive dash cam and ELD data in select states. Sentry publishes up to 3% for ELD data, up to 5% for ELD plus dashcam. Both require data sharing, not just installed hardware. Treat any figure above that range as marketing until someone shows you the filed rate.
A well-used telematics deployment on an idle-heavy fleet usually pays back inside the first year on fuel and verified hours alone. A deployment nobody looks at becomes an expensive map within about six months, and the published decay rate predicts exactly that.
The variable isn't the hardware. It's whether somebody reads the reports.
Build it from your own numbers rather than trusting a quoted figure — no independent source publishes a measured payback period, and every "60 day ROI" claim we traced came from vendor marketing. Take your idle hours, multiply by the Argonne burn rate for your vehicle class, multiply by current EIA diesel, and compare against install plus subscription cost.
The most rigorous independent figure is 6.6% average, with a 95% confidence interval of 4.9% to 8.3%, from a UC Davis meta-analysis of 17 studies. Targeted idle reduction usually does better than that because you're eliminating a specific behaviour rather than nudging an average.
Driver habituation. The same UC Davis analysis measured a decline of roughly 0.1% per day in the effect of onboard feedback. The fleets that keep their savings review reports weekly and coach the outliers. If nobody will own that in your business, discount your ROI estimate accordingly.
Only at a realistic size. Verifiable programmes sit around 3–10% — GEICO up to 10% for new commercial policyholders sharing dash cam and ELD data in select states, Sentry up to 3% for ELD and up to 5% for ELD plus dashcam. Both need data sharing consent. Don't budget on the 30% figures that circulate without a filed rate behind them.
We install across Georgia, South Carolina and North Carolina and we're happy to talk through the arithmetic for your specific fleet before you commit to anything. If the numbers don't support it yet, we'll say so — and if you'd rather prove it on five vehicles before doing forty, that's a sensible way to start.
Get a free quote from API Signal → or call/text 803-513-1009. We install across Georgia, South Carolina and North Carolina, and we come to your yard.
We install GPS, cameras and telematics across GA, SC & NC — at your yard, on your schedule.