There are lots of fantastic stories about the capabilities of the Hummer. One of the biggest ones is the vehicle’s water fording prowess.
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You might have seen the video where a Hummer was completely submerged in a dirty swamp and made it out unscathed.
But can your everyday Hummer H1 or H2 withstand such rigors?
In this article, we look at the water depth of the different Hummer models and its military cousin the Humvee. At the end of this piece, have a clear idea of the water depth a Hummer can handle safely without destroying onboard systems.
Can A Hummers drive in water?
All hummers can drive in water. In fact, Hummers can even be submerged for a short time. They are built for extreme conditions. However, you need to pay attention to the air intake and the electronic parts.
But it appears only the sinewy H1 can hold its own for longer under water because it has fewer creature comforts. But we will get to that later.
Let’s look at the water depths each Hummer can handle.
How Does The Hummer H1 Handle Water?
According to the manufacturer, the H1 can ford water depth of 30”. The vehicle can ford through 30″ water at a speed of 5 mph and 20″ of water at 20 mph.
However, this is only possible in the diesel variant. AM General introduced gas-powered Hummer H1s in 95 and 96.
The gas-powered Hummers can only ford through 24″ of water. This is partly because a gas engine requires a high-voltage spark ignition that can stall when wet.
A diesel engine does not suffer this weakness as it requires no ignition to combust the fuel but uses compression. Also, the diesel engine is sealed, and this reduces the chances of water getting into it.
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Why The Hummer H1 Has Higher Water Fording Capabilities
Of all the Hummers, the H1 has the best chances of getting through water without failure.
In fact, multiple auto reviewers and private owners have tested the H1’s water fording strengths beyond the AM General’s quoted 30″. And the vehicle has performed with excellence.
In one occasion, a driver plowed his Hummer H1 through Texas floods of biblical proportions and made it through without incident.
The H1 can stomp through floodwater and rivers with ease thanks to its hefty bulk of over 10,000 pounds. This allows it exceptional surefootedness even in swift moving water.
Many people wonder why cars get swept off in floods. They forget that vehicle manufacturers prioritize weight reduction to lower cost and boost fuel efficiency.
But the Hummer wasn’t built to be fuel-efficient; it was designed to deliver military capabilities in a civilian setting.
Add the fact that the H1 is a barebones truck with little frills and thrills.
Earlier versions of the H1 had no air conditioning, CD, electronic controls and even padded seats.
So it was far easier for them to plunge into murky waters and damn the consequences.
The H1’s air intake is higher than that of everyday vehicles. This prevented water from flooding the exhaust and finding its way into the engine compartment.
Plus, the breathers were also positioned higher to improve airtightness.
The H1 was designed to be water-friendly, so you can wash it inside out without fear of shorting electrical circuitry or soiling premium leather trimmings.
How Well Does The Hummer H2 Drive In Water?
The Hummer H2 can ford through 30″ of water at 5 mph and 20″ of water at 20 mph, according to stats from GM and AMG.
Unlike its bigger cousin the H1, the H2 is more civilianized, so it comes with many features that have no affinity for water.
The vehicle’s air intakes are lower; it is smaller and weighs only 6400 pounds, almost 4000 pounds less than its bigger cousin.
This means that the H2 will struggle to maintain a foothold in running water, especially if it has to drive for a long time.
Unlike the H1, the H2 is unsuitable for water because it lacks the former’s amphibious capabilities.
First, its air intakes are lower so the chances of breathing in water and damaging the engine are higher.
It also appears like the transfer case and other vital systems are not sealed and the spark plugs are exposed.
The H2 is a big SUV, so it comes with leather seats, climate control systems, high-end entertainment equipment like Bose speakers and CD players.
All these gadgetries and comfort dislike getting wet. So it is understandable that the H2 can wade through less water.
But its capabilities are still legendary compared to other trucks of its size. You will have no problem crossing 3 feet deep streams and rivers.
How Well Does The Hummer H3 Drive In Water?
Despite being smaller at 4,700 pounds, the Hummer H3 shared almost the same water fording capabilities of the H2.
It can ford through 27″ of water at 5 mph and 20″ at 20 mph. The lower water depth is because the H3 had an on-road bias with even more creature comfort, a smaller-sized body and lower ground clearance.
But there are options that deliver exceptional off-roading performance with 33″ tires, armored undercarriage, and differential lockers.
If you want to get the best from your H3, it’s better to avoid using it to cross deep water now and then.
The vehicle’s body may be better sealed, but its undercarriage may not withstand long-term exposure to moisture.
The Humvee, i.e., the military version of the Hummer was designed from scratch to wade through deep water.
We may never know the full amphibious capabilities of this battle wagon, but GIs have reported pushing the Humvee beyond its limit in the heat of combat.
The HMMWV can ford 30 inches normally but this can increase drastically if you install the deep fording kit.
With the fording kit, the Humvee can wade through 5 feet deep water, and it can even be submerged completely.
It will interest you to know that operators often hide their Humvees by parking it underwater.
But even the military does not encourage such acts, and it advises users to limit the use of the Humvee to 30″ deep streams.
Why Humvees Are So Water-Capable
But why does the Humvee have better water fording capabilities than its civilianized cousins?
Well, the military requires efficiency and reliability over fancy systems. Military Humvees have very little electronic components.
The transmission, fuel pumps, brake booster, and other systems are mechanical, building a lot of redundancy into the vehicle.
There is no AC, carpet or multi-CD entertainment system; soldiers make do with their waterproof and impact-resistant two-way radios and GPS hardware.
And the operator can direct all the vents to CDR valves at the top of the engine, making critical systems air-tight.
Besides, the wiring, gauges and transmission control are waterproof.
The Humvee also lacks the cushioned interior of civilian Hummers, so there is no fear of getting wet.
It can plunge into the water with reckless abandon. But operators still have to follow standard operating procedures to ensure safety and survivability.
What Happens When You Drive Hummers in Water That Is Too Deep?
The manufacturer warns that drivers should not exceed their Hummer’s fording depth of 24″-30″ based on the model. Sadly, not everybody will get the message.
If you submerge your Hummer in water that is too deep, you risk hydro locking the engine.
The main reason for this is that the Hummer’s electrical and transmission systems are not waterproof. You can seal the systems with aftermarket solutions, but they don’t come from the factory that way.
Under water above 30″, you risk tanking your transmission control system, electrical system, and worse the engine might take in water.
Whether you are wading through floodwater or crossing a stream on the trail, be wary of any water that covers the hood of your Hummer.
There is a high chance of hydrolocking your engine, especially if you are moving fast. Thankfully, the hood shape helps to deflect the bow wave away from the air intake.
A hydrolocked engine may not be a big issue if you are idling the engine. But if the engine is running above idle, hydrolock can cause serious damage.
It can bend, break and twist the pistons, crack the cylinder, blow oil seals, and even under your engine block.
2 Ways to Increase Your Hummer’s Water Fording Depth
Civilian hummers can use the military deep fording kit. And you can DIY the work by waterproofing the vital systems that must not be compromised when crossing water.
1) Raised Air Intake
The air intake must be elevated enough so it is always out of the water. An easy solution to this is to install a snorkel.
Hummer H1s have their air intakes high up. Air intakes are good for crossing deep water.
They can also prevent the engine from sucking sand when driving in off-road conditions such as deserts.
2) Sealed Electronics and Transmission
Another big problem when fording water in a Hummer is the risk of shorting electrical connections and a flooded tranny. To prevent expensive repairs, it’s crucial to keep the transmission control computer and electrical wiring watertight.
A Hummer can wade through water, but always remember that it is not an amphibious vehicle. Whenever you need to wade through water, it’s vital to stick to the manufacturer-recommended limit.
But if your habits require frequent contact with water, it’s better to go for a Hummer H1 with its barebones design, hulking size, and manual controls.