Which is the better power plant?

[WA454]

Ok, I have been shopping for a 5 ton for a while, and I thought it was to be an A2. I like the super singles, and turbo motor. My past experiences with N/A Diesels were pretty unimpressive. Now I am reading on here that the A2 has pretty substantial turbo lag, and the A1 has more low end torque. So I guess my question is, which of the modern 5 ton power plants is the best in the real world. I am sure that some of you guys have some seat time behind the wheel. To throw in a curve, the idea of a stick shift is very appealing to me. How would an A0 stack up with the A1, and A2?
Thanks, Bill

 

[jdknech]

Only difference in the A0 and the a1 is tires.. I converted mine from a "0" to a "1" and can't tell a difference in power. I like the 855 cummins (250) because it has more low end power. To me the best power plant though, would be a "big cam" 350 cummins it's also a 855ci (this would have to be swapped in)

 

[Triple C]

I was surprised at how doggy the NA250 was. I hadn't driven a big truck for a number of years and the last one I drove was an N14 with a Rockwell 9 behind it but I have found the 250 with the auto to be slow and pretty unresponsive. I have never had a load on my 925 so I don't know what it would do with a load of rock or dirt. On the other hand, I am not in any hurry either so it really doesn't matter, I was just surprised. I like the 855 block a lot though. In years past I put almost 600,000 miles on a 350 - 855 block, it was a great motor. If I could change one thing, it would be to have a stick shift.

 

[TurboMustang370]

I can't give you a comparison since I've never driven a 250 in a 5 ton but the CTA8.3 turbo motor is a blast to drive off-road and has no problems maintaining 55mph on the county roads.

 

[WA454]

I can't give you a comparison since I've never driven a 250 in a 5 ton but the CTA8.3 turbo motor is a blast to drive off-road and has no problems maintaining 55mph on the county roads.

So no turbo lag?

 

[emr]

wa454, You have to start from the basics, if you do not know the difference between the 3 trucks to start off,use the search function and get a background first like it is suggested on this site, then you can fine tune your question and learn a ton more, what you are asking to be honest is so minor . These are tactical trucks first and for most, anyone surprised about how doggy they are do not understand what they are and what they are designed for, if you are thinking over the road, you really should consider a civy truck set up, just an fyi... There have been a few thou questions on this and there is a vast amount of answers, you must consider more than one post to learn about them, Then to be honest you need to spend time behind the wheel, i am not wealthy , but i took the time to buy 2 dueces 2 five tons and a cckw352 after wanting to know that facts that i needed to know, and most of the time you need to be in them to really know, all you are getting on the inter net is mostly opinion, Buy and sell a few and you will enjoy them and learn more than you could ever know... good luck,

 

[emr]

Turbo lag ? i think you expect allot more than these trucks are ever going to do for you ... fyi...I have driven both 5 tons 809 and 939 series and deuces same day same big snow storms, tow barred all of them one way or another to each other, the 2- 5 tons pulled the sled at a tractor pull so i will tell you one is not better than the other, they do different things, if you search you will find the 809s trans is geared to low not by mistake and is truly awesome if you understand they are tactical vehicles, and the auto is tough as can be, but as different as an auto to a shift can be, you must drive them, the 2 -939 motors are as close as 2 different motors can be in performance. some A0 A1s at the facility run better than the A2s, and visa versa .

 

[WA454]

wa454, You have to start from the basics, if you do not know the difference between the 3 trucks to start off,use the search function and get a background first like it is suggested on this site, then you can fine tune your question and learn a ton more, what you are asking to be honest is so minor . These are tactical trucks first and for most, anyone surprised about how doggy they are do not understand what they are and what they are designed for, if you are thinking over the road, you really should consider a civy truck set up, just an fyi... There have been a few thou questions on this and there is a vast amount of answers, you must consider more than one post to learn about them, Then to be honest you need to spend time behind the wheel, i am not wealthy , but i took the time to buy 2 dueces 2 five tons and a cckw352 after wanting to know that facts that i needed to know, and most of the time you need to be in them to really know, all you are getting on the inter net is mostly opinion, Buy and sell a few and you will enjoy them and learn more than you could ever know... good luck,

OK, I have been researching for several years. I know the basic differences. I realize two like vehicles will run differently. I am just looking for opinions on which is more fun to drive, after all, this is for fun, right? I don't think I will be buying one of each though!

 

[seano11]

The 8.3 hands down once that turbo spools your gone kinda like driving a corvette. If you don't like the lag and our into drag racing these bad boys hold your foot on the brake and gas till that turbo is spooled. I think they do the 1/4 mile in 9.4 seconds. Or was that minutes ?

 

[quickfarms]

Some people say these trucks, the 900 series 5 tons, are quick off the line other people say they are dogs. This could be caused by several factors. The different engines are a small factor. The transmission shift point settings are a big factor. Another factor is the driver. Driving an automatic is much different than driving a stick. When driving an automatic you bring the RPM up to the first shift point and hold it there. This RPM should be about 300 below the governed RPM of the engine if the transmission is set per Allison specs. This should be about 2500 RPM.

 

[Csm Davis]

It is also according to what truck you are talking about and what you are going to use it for. For my money a wrecker should have a big OTR motor ie 250 or bigger and stick shift. Bobbed playtoy 8.3 because it is lighter and auto would be nice to run around town in. So give us something to go on to gage your usage.

 

[kdaniels]

This is a really tough question for a couple of reasons.....most of us who have more than one of the same truck ie M37....M35.....or M923 know that EACH truck has it's own personality....three of the same trucks sitting on a lot each one will drive and preform differntly. WHY ??? I have no clue..maybe it was how it was broke in or maybe how it came out of rebuild the last time..who knows. That's were friends and clubs come in so you can compare notes..... Just sayin

SEMPER FI !!

keith

 

[commandojeff]

Are you going to want historic plates for your truck? If so then the A2 might not be for you. My A1 seems pretty peppy for what it is. Obviously this is not the type truck most people are used to driving. But from the other MVs I have driven... The 250 gets up and goes very well. Plus it will pull anything you will realistically hook it to. It is hard to get that much weight moving (or stopping) in one direction very fast. You will love either truck.

Also will you ever need the CTIS? No. Will you ever use it? No. To me it's just more things that can go wrong that I don't want to deal with. Now if I had a use for the system in what I want to use the truck for, then I would be all for it.

 

[Triple C]

I think the point that emr and commandojeff as well as others make is an important one. Some of us were not in the military and had no previous experience with military vehicles. I think their point that these are tactical vehicles is an important point. My 925 is a completely different animal than the freightliners I drove. As I posted earlier, it surprised me but in consideration probably shouldn't. The question of what it is going to be used for (as in my case, a hobby which makes road performance rather unimportant) so your use may dictate your choice. I don't know what parameters you need to consider it fun, but maybe if you could drive one...... If you were closer you could take mine for a spin. Either way, welcom to the site and I hope your purchase journey is a fun one.

 

[supermechanic]

Simpler is better in my book, hard to kill the old cummins.
It's also hard to stay with traffic using one.
If you are in a hurry,hot rod a deuce.

 

[WA454]

It is also according to what truck you are talking about and what you are going to use it for. For my money a wrecker should have a big OTR motor ie 250 or bigger and stick shift. Bobbed playtoy 8.3 because it is lighter and auto would be nice to run around town in. So give us something to go on to gage your usage.

I will probably just use it as a cruising toy with occasional off road use. Been eyeing tractors, as I like the short wheel base. I may do a bob job eventually.

 

[WA454]

Some people say these trucks, the 900 series 5 tons, are quick off the line other people say they are dogs. This could be caused by several factors. The different engines are a small factor. The transmission shift point settings are a big factor. Another factor is the driver. Driving an automatic is much different than driving a stick. When driving an automatic you bring the RPM up to the first shift point and hold it there. This RPM should be about 300 below the governed RPM of the engine if the transmission is set per Allison specs. This should be about 2500 RPM.

So, if I am reading this right,these trucks are tunable, and the possible difference in the way similar trucks run is "state of tune"?

 

[quickfarms]

The shift points for the transmission is programmable by an Allison service station. You have to remove the pan to adjust them.

 

[wreckerman893]

I have the 8.3 in my M927. It has the CTIS and super singles. I have never used the CTIS and prob won't since one of the wheels is blocked off. The 8.3 is peppy considering how heavy the extended WB is. It also has a big tuning radius. One thing that almost all stock MV's have is their aversion to hills. No MV I ever had was fast going uphill with a load on it. Even empty I'll lose speed on a steep grade. One good thing about the 8.3 is the quiet.....it's a lot quieter than the 250 by far.
Since I've owned a 900 series 5 ton it will be hard to go back to a deuce.

 

[Farmallmilitary]

Also if you like the loud diesel engine sound get the 250 cummins i love the sound of that 855. They are pretty much bulletproof and just driving it around it sure seems to have quite a bit of power. I haven't put a very big load on it but when off roading it has plently of power even if you were to use high gear. I haven't actually driven an a2 but my buddies have and they say if you want more power for those long hills the 250 does better. Myself i like the sound of the na engine but remember it is all opinion and what you want. If you were closer i would let you drive mine but you being in fl and me being in nm i doubt that would be possible. Ha. Good luck. Either way you go you will definetily love it. I mean how couldnt you love a 5 ton military truck!