Autoterm Air 2D
#3 in SplitFull review
For van and boat owners who want a type-approved 2 kW heater for less than Webasto or Espar. Add a timer panel if you want it warm before you wake.
Amazon $949.99$949.99
The Autoterm Air 2D is the better diesel heater overall, rated 3.5 to 3.3. The Autoterm Air 2D costs $925.01 less ($949.99 vs $1,875).
Webasto Air Top Pro 25
#7 in SplitFull review
For van and truck owners who want a new type-approved 2 kW heater with altitude adjustment and a very low idle setting, or a drop-in replacement for an Air Top 2000 STC. It costs far more than clone heaters of the same size.
VMACS $1,875$1,875
Prices were last checked October 30, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every split diesel heater; a clear win is highlighted. How we rank explains each one.
| Factor weight | Autoterm Air 2D | Webasto Air Top Pro 25 |
|---|---|---|
| Overall rating | 3.5/5 | 3.3/5 |
| Value 25% | 7 $475 per kW ($949.99, 2 kW) | 0 $750 per kW ($1,875, 2.5 kW) |
| Type approval 20% | 100 type approved (ECE R122) | 100 type approved (ECE R122) |
| Controls and safety 15% | 50 holds a set temperature, automatic altitude; no CO sensor | 50 holds a set temperature, automatic altitude; no CO sensor |
| Power draw 15% | 69 up to 29 W running | 50 power draw not published (neutral score used) |
| Warranty 15% | 50 2-year warranty | 50 warranty not published (neutral score used) |
| Low setting 10% | 100 down to 0.8 kW | 100 down to 0.7 kW |
Specifications
| Autoterm Air 2D | Webasto Air Top Pro 25 | |
|---|---|---|
| Heating | ||
| Heat output (maker) | 2 kW | 2.5 kW |
| Lowest output | 0.8 kW | 0.7 kW |
| Fuel burn | 0.1 to 0.24 L/h | - |
| Build | Split (installed) | Split (installed) |
| Power | ||
| Supply | 12V | 12V |
| Running draw | 10 to 29 W | - |
| Controls and safety | ||
| Thermostat | Yes | Yes |
| Automatic altitude | Yes, to 13,780 ft | Yes, to 18,045 ft |
| App | No | No |
| Timer | No | No |
| Remote | No | No |
| CO shutoff | No | No |
| Type approval | ECE R122 | ECE R122 |
| Build | ||
| Dimensions | 12.2 x 4.7 x 5.7 in | 12.6 x 5 x 4.9 in |
| Weight | 6.4 lb | 6.5 lb |
| Warranty | 2 years | - |
| Released | - | 2026-07 |