Espar Airtronic M2 D4L
#8 in SplitFull review
For larger vans, sleeper cabs and boats that need a type-approved 4 kW heater with a wide turndown. The M3 D4L that replaces it costs the same and draws less power.
Amazon $1,675$1,675
The Espar Airtronic M2 D4L is the better diesel heater overall, rated 3.2 to 2.9. The Espar Airtronic M2 D4L leads on type approval, low setting and controls and safety. The LF Bros Split T3 5kW Diesel Heater wins on value. The LF Bros Split T3 5kW Diesel Heater costs $1,485.01 less ($189.99 vs $1,675).
LF Bros Split T3 5kW Diesel Heater
#19 in SplitFull review
A basic 5 kW split kit for truck, RV and boat installs, with a timer but no thermostat.
Amazon $189.99$189.99
Prices were last checked November 2, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Which should you buy?
- Choose the Espar Airtronic M2 D4L for type approval (type approved (ECE R122) vs no type approval published), low setting (down to 0.9 kW vs down to 1.4 kW) and controls and safety (holds a set temperature, automatic altitude, timer; no CO sensor vs timer; fixed levels only).
- Choose the LF Bros Split T3 5kW Diesel Heater for value ($38 per kW ($189.99, 5 kW) vs $419 per kW ($1,675, 4 kW)).
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 | Espar Airtronic M2 D4L | LF Bros Split T3 5kW Diesel Heater |
|---|---|---|
| Overall rating | 3.2/5 | 2.9/5 |
| Value 25% | 11 $419 per kW ($1,675, 4 kW) | 87 $38 per kW ($189.99, 5 kW) |
| Type approval 20% | 100 type approved (ECE R122) | 0 no type approval published |
| Controls and safety 15% | 65 holds a set temperature, automatic altitude, timer; no CO sensor | 43 timer; fixed levels only |
| Power draw 15% | 40 up to 42 W running | 50 power draw not published (neutral score used) |
| Warranty 15% | 0 warranty not published, scored as none | 0 1-year warranty |
| Low setting 10% | 92 down to 0.9 kW | 50 down to 1.4 kW |
Specifications
| Espar Airtronic M2 D4L | LF Bros Split T3 5kW Diesel Heater | |
|---|---|---|
| Heating | ||
| Heat output (maker) | 4 kW | 5 kW |
| Lowest output | 0.9 kW | 1.4 kW |
| Fuel burn | 0.11 to 0.51 L/h | 0.18 to 0.53 L/h |
| Fuel tank | - | 10 L |
| Build | Split (installed) | Split (installed) |
| Power | ||
| Supply | 12V | 12V |
| Running draw | 6 to 42 W | - |
| Starting draw | 100 W | - |
| Controls and safety | ||
| Thermostat | Yes | No |
| Automatic altitude | Yes, to 9,840 ft | - |
| App | No | - |
| Timer | Yes | Yes |
| Remote | No | - |
| CO shutoff | No | - |
| Type approval | ECE R122 | None published |
| Build | ||
| Dimensions | 14.8 x 5.5 x 5.9 in | 14.9 x 5.6 x 5.9 in |
| Weight | 9.9 lb | - |
| Warranty | - | 1 year |
| Released | 2018-07 | - |