AM General HMMWV (Humvee)

AM General HMMWV (Humvee): Which Version to Choose?

The AM General HMMWV (Humvee) catalogue contains one generation, produced from 1984 to 2006 as an SUV 5-doors, and two versions: 6.2 AT and 6.5 AT. Since both versions share AWD, a 3-speed Automatic gearbox, a top speed of 113 km/h, a 95-liter tank, a kerb weight of 2,359 kg, and 250 mm of ground clearance, the buying decision mainly concerns the engine.

The AM General HMMWV (Humvee) catalogue contains one generation, produced from 1984 to 2006 as an SUV 5-doors, and two versions: 6.2 AT and 6.5 AT. Since both versions share AWD, a 3-speed Automatic gearbox, a top speed of 113 km/h, a 95-liter tank, a kerb weight of 2,359 kg, and 250 mm of ground clearance, the buying decision mainly concerns the engine. The 6.2 AT has a 6,200 cm³ Diesel producing 150 hp, while the 6.5 AT has a 6,500 cm³ Turbo Diesel producing 180 hp and 366 Nm. On the available figures, the 6.5 AT is the stronger choice; the 6.2 AT is the alternative for buyers who do not need the extra 30 hp.

Generation and version comparison

There is only one HMMWV (Humvee) generation in the supplied catalogue, so there is no choice between generations or documented generational change to compare. The 1 generation ran from 1984 through 2006, used the SUV 5-doors body, and included two versions. Both the 6.2 AT and 6.5 AT are listed for the full 1984–2006 period.

Searches for model years such as 1987, 1990, 1992, 2000, 2002, and 2006 therefore fall within the recorded production period. Years after 2006 fall outside the dates supplied here, so this catalogue data cannot confirm specifications for them. Likewise, the data does not identify an M998 version or any restyling; assigning either engine to such a designation would go beyond the available facts.

Engine specs: 6.2 AT vs 6.5 AT

Each engine has 8 cylinders in a V-shaped layout and 2 valves per cylinder. The 6.5 AT increases displacement by 300 cm³, power by 30 hp, and output by 22 kW over the 6.2 AT. This represents 20% more horsepower from an engine that is about 4.8% larger by displacement.

Power per liter is approximately 24.2 hp for the 6.2 AT and 27.7 hp for the 6.5 AT. The Turbo 6.5 AT therefore produces about 3.5 more horsepower per liter, an improvement of roughly 14.6% in power density.

For the 6.5 AT, the supplied specifications also include a compression ratio of 21.5 and a bore and stroke of 102.9 × 97 mm. Compression ratio and bore-and-stroke measurements for the 6.2 AT are not measured. Engine position and fuel-system type are not measured for either version.

Performance, top speed, and mpg

Both the 6.2 AT and 6.5 AT have a recorded maximum speed of 113 km/h. Despite the 6.5 AT having 30 hp more, the supplied data shows no difference in top speed.

Acceleration from 0 to 100 km/h is not measured for either version. City fuel consumption, highway fuel consumption, and combined fuel consumption are also not measured for both engines. Consequently, an mpg figure cannot be calculated, and the available data does not support a claim that either version is quicker from rest or more economical.

CO₂ output and emissions class are not measured for either the 6.2 AT or 6.5 AT. Fuel grade is also not measured, although the engine type is listed as Diesel in both cases.

Weight, dimensions, and ground clearance

The 6.2 AT and 6.5 AT each have a kerb weight of 2,359 kg. Gross weight is not measured for either version. Overall length, width, and height are not measured in the supplied data.

Both versions provide 250 mm of ground clearance and a 95-liter fuel tank. Wheel and tire sizes are not measured for either version.

Because kerb weight is identical, the engine comparison can be made directly through weight per horsepower. The 6.2 AT carries approximately 15.7 kg for every horsepower, while the 6.5 AT carries approximately 13.1 kg per horsepower. The 6.5 AT reduces the weight-to-power burden by about 2.6 kg per horsepower, or roughly 16.7%.

Both versions use Independent, spring front suspension and Semi-independent, spring rear suspension. Front and rear brakes are Disc on both versions. The supplied specifications therefore reveal no chassis, clearance, tank-capacity, braking, or kerb-weight advantage for either engine.

Reliability and problems

Reliability ratings, failure records, maintenance costs, and model-specific problems are not measured in the supplied data. It would therefore be inaccurate to declare either the 6.2 AT or 6.5 AT more reliable.

The specifications do establish that the 6.5 AT uses Turbo boost, whereas boost for the 6.2 AT is not measured. They do not establish how that difference affects durability, servicing, or operating cost. Buyers comparing individual vehicles should treat condition and maintenance history as separate questions because neither is included in this catalogue dataset.

Which HMMWV (Humvee) version should you buy?

Choose the 6.5 AT if the priority is the strongest specification available here. It delivers 180 hp and 366 Nm, compared with 150 hp and an unmeasured torque figure for the 6.2 AT. Its extra 300 cm³ buys 30 hp, while kerb weight remains 2,359 kg and the shared 113 km/h maximum speed, 250 mm ground clearance, 95-liter tank, AWD, and 3-speed Automatic gearbox do not change.

Choose the 6.2 AT if 150 hp is sufficient and the additional output of the 6.5 AT is not required. The data provides no fuel-consumption, acceleration, reliability, or price evidence that would prove a financial advantage for either version, so there is no factual basis here for claiming that the 6.2 AT is cheaper to own or that the 6.5 AT is faster to 100 km/h.

On specifications alone, the 6.5 AT is the clear recommendation: it offers 20% more horsepower, about 14.6% greater power per liter, and about 16.7% less weight per horsepower without an increase in recorded kerb weight. The case for the 6.2 AT depends on factors such as price or vehicle condition, but those factors are not measured in the supplied data.