Humvee Info – How Fast Is A Military HMMWV?

Humvee Info – How Fast Is A Military HMMWV? Yeah. We hear this question a LOT. Here is some info from folks smarter than me to finally put this question […]

Humvee Info – How Fast Is A Military HMMWV?

Yeah. We hear this question a LOT.

Here is some info from folks smarter than me to finally put this question to bed!

HMMWV with 3 speed transmission

“Redline on the 6.2 and 6.5 motor is 3400 RPM. That’s about 67-70 MPH with the three speed trans 1:1 final, 2.73 diffs and a 1.9 ratio in the geared hub and 37″ tire (which measure 36”). I don’t like running at redline so 55-60 max with the three-speed.” -Clarke F

In response to someone saying he drives his 6.2L, 3 speed HMMWV 80 MPH and “…if I maintain oil pressure and keep it clean , I know it won’t hurt it” Michael H said “…infact your wrong. Pushing an engine like this to high RPM will definitely blow it up. Heavy pistons, rods, with low quality retainer springs are not meant for high RPM. A piston will slap a valve due to the spring not being able to pull it back in time. Or you will crack a push rod… 4200 rpm is prob this engine’s red line. But I will dbl check that now. Also it may not have an rpm governor” and followed a few minutes later with “Ok looks like 3600rpm max”. 

 

HMMWV with 4 speed, overdrive transmission

“So with the 4 speed at .75 final [drive ratio], 67mph should be about 2500 rpm. I’ll take that.” -Lucas F
“It’s not to go 80mph, it’s about, less stress on engine, less noise, less heat, better mpg (well…). If you want to drive it 80 you bought wrong vehicle.” -Andre K

But is it SAFE?

First, when I ask “is it safe”, I don’t mean safe for the driver. If you choose to drive too fast and kill yourself that is on you. We are all adults here.
The “safe” I am referring to relates to everyone else on or around the roads HMMWVs are driven on. Who are you going to hurt when you lose control of your HMMWV at 80 MPH?

I think it is unsafe to go 80 in a surplus HMMWV that has had who knows what abuse over it’s life. I may be convinced that a HMMWV with a 4 speed, overdrive transmission and balanced tires might safely hit 80 on occasion IF it has been thoroughly inspected to be sure everything is right. Especially the hubs, tires, steering and brakes.

TIRED of this question…

I also don’t think the surplus military tires that most of us run are safe for that sort of speeds. We don’t know how they were stored, how old they are, if they have been abused, exposed to UV or chemicals or anything else such that their integrity may be compromised. Also don’t know how badly out of balance they are and what magnitude imbalance issues present themselves as speed increases. Most may be OK at that speed, but it only takes one blowout at 80 for someone to lose control and kill people.

“I don’t care if I blow up my 6.2”

Heard this more than a few times from guys that are looking for an excuse upgrade to the 6.5L or a different engine. So, a cautionary tale about engine parts ejecting themselves from the vehicle at Interstate speeds…

My brother came REALLY close to totally losing control of his truck on the interstate going 75-80-ish when his engine threw a rod down through the oil pan.
Everything was fine, then BOOM! He didn’t feel it coming. Something that came loose (probably the rod) hit and ruptured a front tire. He still swears he has no idea how he kept control. Scared the crap out of him. My grandparents were in the back seat and thought for sure they were going to die.
While he was trying to keep from completely losing control of the truck he was ALL OVER the Interstate and nearly took out a few other vehicles.
So, yeah. I do think that attempting to blow up your engine on public roads can endanger those around you.

Conclusion

Top safe speed for a 6.2L equipped HMMWV with a 3 speed transmission is in the 55-60 MPH range. These aren’t like speed limits where most folks assume it is OK to go 5-10 MPH over.

Top safe speed for a 6.5L equipped HMMWV with a 4 speed overdrive transmission is probably going to be limited by other factors like tire balance and overall vehicle condition. The drivetrain can handle the top speeds allowed in the US.

Where to get Humvee, M35A2, M923 & military vehicle parts:

Help us share more reviews!

If you’d like to support Gear Report for free, please use the links below for online shopping. This is huge and really helps. Thank You!

Use our Best Price Search page to find the best deals on any product you are looking for.

You can find a lot more links on our Merchant Links page.
Here are some of the most popular:

 Suggestions?

Please leave a comment if you have suggestions on other products we should consider reviewing, please let us know in the comments.

Where to buy Silencers?

You can legally purchase silencers online and have them shipped to your local SOT FFL, who will help you with the ATF Form 4 transfer process. Here are some links to trusted retailers who sell suppressors.

Quarter Horse Arms - machine gun from HMMWV

Jeff shooting the Quarter Horse Arms AR15 Full Auto from the Project Humvee Battlewagon

The Project Humvee Battlewagon

Gear Report acquired a real HMMWV (High Mobility Multipurpose Wheeled Vehicle) from the US Army for use as our official field and shooting range vehicle. We have already posted about some of our upgrade projects (Project Humvee Battlewagon article links) and have a lot of really cool projects on the way. Consider subscribing so you don’t miss any of the cool reviews as we post them.

Here is our Project Intro (link) and our list of HMMWV upgrade projects.

The Deuce Utility Vehicle (D.U.V.) Project M35A2

The D.U.V. project started with a fairly standard 1968 M35a2 two and a half ton 6×6 cargo truck. Commonly known as the “Deuce-and-a-half” or “The Deuce.” We aren’t yet sure where it will stop.

 Gear Report YouTube channel

Subscribe for Great Reviews (link)

About Jeff

Jeff is the Editor in Chief of Gear Report and a National Shooting Sports Foundation Media member. He reports on the outdoor industry, reviews gear for camping, hiking, shooting, hunting, paddling, backpacking and other active pursuits. A USAF veteran, Jeff earned a MBA in Marketing and Health Services. He specializes in consultative selling and internet marketing. As the VP of BD & Marketing, Jeff provides sales and marketing leadership to MGECOM, Inc. and helps http://MGECOM.com acquire new clients in need of solutions for online merchants in need of Affiliate Marketing program management. Jeff founded and manages Cress Sales & Marketing LLC, offering online sales and marketing consulting and services to online merchants and service providers.