m998a1 mpg

[desmodromic]

Not anymore.

 

[Action]

Manual states range is 250 miles.
25 gal tank.
10 mpg

 

[Havok]

I get a pretty consistent 11 mpg. At highway speeds (50mpg) I'll go through about a 1/4 of a tank round trip if I take it to work, which I do about once or twice a month.

 

[springbok]

Well because I am usually towing a broke down Jeep for someone I am lucky to get 5 mpg
Actually, my MPG is simple, when at 1/4 tank fill it up, always keep a 5 gallon Jerry can of fuel with you..

 

[coggonobrien]

What has been done successfully to increase mpg? Anybody in hear successfully swapped to an overdrive?

 

[porkysplace]

What has been done successfully to increase mpg? Anybody in hear successfully swapped to an overdrive?

Buy a Prius if your worried about MPG.

 

[dhaumann69166]

When I refuel and someone asks me about fuel mileage in my hmmwv, I say it gets over 20 mpg. The look on their confused faces is priceless. It takes the wind out of their sarcastic reply.

Glad to hear I am not the only one that does that! I tell people that same thing for both my 93 HMMWV and the wife’s H2. They always respond with “really I thought they did horrible” and I always just say “that’s what I always heard too”. Used to drive a 99 Cummins that got 28mpg. Was always fun to be able to prove to people my 3/4 Diesel got better mileage than their rice burner.

 

[coggonobrien]

Buy a Prius if your worried about MPG.

With a modern f350 weighing just a few hundred pounds less than a hmmwv, there is no reason with a properly tuned diesel and the correct final drive ration that we shouldn't be able to get at least 15mpg at 60 mph

 

[porkysplace]

With a modern f350 weighing just a few hundred pounds less than a hmmwv, there is no reason with a properly tuned diesel and the correct final drive ration that we shouldn't be able to get at least 15mpg at 60 mph

And if read through and search the HMMWV forum you will probably come up with a 100 threads on it ,some with posts from the last few days. Also your comparing a "modern F350" to a 30 year old tactical truck with a turd for a motor.Most anything is possible if yoiur pockets are deep enough.

 

[coggonobrien]

I searched through the forum and like all other forums I belong to find hundreds of what if's without any real attempts. Does this forum tend to be people who stick with factory equipped or are there a few guys who start customizing

 

[porkysplace]

I searched through the forum and like all other forums I belong to find hundreds of what if's without any real attempts. Does this forum tend to be people who stick with factory equipped or are there a few guys who start customizing

209 threads searching "overdrive transmission" . It includes Cummins swaps, gas swaps and several different model tranny swaps.

A Cummins swap from 7 years ago ;
[h=1]New Cummins HMMWV project in the works![/h]

https://www.steelsoldiers.com/search.php?searchid=6094248

 

[ken]

I installed a Huges Perfomance GM5 fuel miser torque converter when I installed the 6.5. I will report if there is any improvement.

 

[VegaCP]

How did this end up working out for you?

I installed a Huges Perfomance GM5 fuel miser torque converter when I installed the 6.5. I will reView attachment 717900port if there is any improvement.

 

[2wheels70]

12-13 religiously and that's mixed driving

 

[98G]

12-13 religiously and that's mixed driving

With a modern f350 weighing just a few hundred pounds less than a hmmwv, there is no reason with a properly tuned diesel and the correct final drive ration that we shouldn't be able to get at least 15mpg at 60 mph

F350 is generally quite a bit heavier than a hmmwv.

My Ram 3500 crosses the scales at just short of 9k empty.

Although the military calls these things a 1 1/4 ton truck, the more realistic comparison is a civvy half ton. Or a Jeep Wrangler JKU.

A quick search yields the following weights -







Back on the topic of fuel economy, I'm seeing 12-15 out of my plain vanilla M998. State highways at 55mph, some in town, and always a 3min idle before shutdown.

I am still of the opinion that the most valid comparison for the hmmwv is the 4 door wrangler. Similar use profile, similar passenger and cargo room/capacity, virtually identical towing capacity, offroad capabilities, and very similar fuel consumption.

I try not to get hung up on fuel costs. I know guys who shut their turbodiesel equipment off the moment they stop, in order to save a few tablespoons of diesel. The cost of the increased wear on the equipment is far more than the fuel saved....

You guys spending $ to improve fuel efficiency may want to do some math - let's say there's a mod to improve by 2.5mpg, which for simplicity's sake we'll call 20%. Call it a cost of $2k to make this modification. The break even point for the cost of the mod is when you've spent $10k in fuel, which is going to be somewhere around 50,000miles. Now factor in that most mods are a tradeoff of performance somewhere else, and it becomes evident that .......

While I'm rambling on the topic of fuel efficiency, it of course often comes up regarding 5ton trucks. My answer - "I get about 6mpg empty." They usually reply with something close to 20mpg... and then I say something along the lines of " but I get about 6mpg loaded 75,000lbs too. What do you get at that weight?" At which point they don't. Different tools for different jobs.

Most of these things are toys. The appropriate measurement isn't how any miles per gallon of fuel. The appropriate measurement is how much enjoyment per $. Using that metric, any of the MVs are hard to beat.

I assert again that the appropriate comparison is a 4 door wrangler. They're also a lot of fun to drive, occasionally have someone eying it up in the parking lot etc. But the hmmwv is more fun to drive, at similar operating costs, and 1/4 the acquisition cost.

 

[2wheels70]

I was actually delighted to find 13 miles per gallon with my m998
I have Street driven 600 horsepower hot rods in the past fuel use is part of the enjoyment tax

 

[ken]

How did this end up working out for you?

I did a 100 mile round trip at 45MPH. I got 15MPG. But mine is a 2door 998. I was empty so i'm probally lighter than most. I have a 6.5NA and the 3 speed. If I ran 50-55 I assume it would have been a lot worse.

 

[2wheels70]

I did a 100 mile round trip at 45MPH. I got 15MPG. But mine is a 2door 998. I was empty so i'm probally lighter than most. I have a 6.5NA and the 3 speed. If I ran 50-55 I assume it would have been a lot worse.

Mine is a 2 door soft top m998 that's the one I get 13 miles per gallon religiously doesnt matter if it's around town or 55 miles an hour

 

[Skrilex]

My economy tuned f350 gets 13.5mpg. Also, this isn’t a fair compare because the f350 has manual hubs and better ratios and smaller tires etc. So about the only way to get a better mpg would be with a cranked up DI diesel like a Cummins and other measures like meth injections etc.

I wish people wouldn’t dismiss mpg as irrelevant in old mill vehicles or any other vehicle. A Boeing 747 uses thousands of gallons of fuel every time it is used, does that mean they don’t care about fuel economy? Does a long haul trucker care about the difference between 6mpg and 7mpg? You bet.

There are plenty of reasons to desire better economy. Range is one. Preserving resources is another. Cost is another. And some people, like me, just plain like being as efficient as they can be regardless of how big and ugly the use happens to be.

Suggesting a Prius is really silly and not helpful to the conversation at all, unless it was a joke in which case it fell a little flat.

 

[ken]

Agreed! My quest for fuel economy is mainly for range. Not so much economy. I do carry 2 jerry cans in each of my MV's but If I can increase 1 or 2 MPG that could make all the difference between walking and driving after a long day of offroading. I'm happy at 15MPG but I will shoot for better.