Isuzu npr 4wd

gator70

Active member
When a creator plans a build it is important to understand a market value for the end product. My guess is $150K USD. There are so many MB sprinter vans costing $250K USA and this is crazy. Recently some nice Fuzo Fg builds with composite habitats could not sell in the $120K USD level. My guess is theses habitats were not finished and some folks want a turn key purchases as they are not skilled to DIY anything.
 

gator70

Active member
Point of reference: I just watched a youtube where a couple detailed the cost of their Isuzu nps and camper build costing $202,000 Australian
 

Peter_n_Margaret

Adventurer
Market value is only useful if you want to sell or buy.
I can not buy what I am building, and I intend to keep it for many years, so, 1) Market value is impossible to determine and 2) it is of relatively little interest to me (except for insurance purposes).
When my project is completed, I will need to sell the existing vehicle. Market value of that is important then, but since it is quite different from others, it is also difficult to establish.
Market value is established by the buyers. You only need one.
Cheers,
Peter
OKA196 motorhome
 
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Ultimark

Active member
Interesting things have happened with vehicle pricing since COVID-19, in general they have gone up quite a lot.

Our Isuzu NPS 300 is a single cab chassis manual model, the cheapest configuration possible. The cab chassis was manufactured in 12/2019, delivery to Australia happened (as far as I can tell) either right at the end of December 2019, or in the first week of January 2020. We purchased it on or about the 10th of January 2020.

The base cost, excluding any government charges or taxes or on road costs for the cab chassis, was $68,495.00 AUD. If you wished for a crew cab model, I seem to remember it was about another $4,000.00 AUD. Adding an AMT (Automated Manual Transmission) added about $4,000.00 AUD as well.

Now on top of that price, we required a tray, super singles, complete suspension change, extra fuel tank, some bar work, extra spare (six wheels) and stuff like that. If you do the maths you can see that before these vehicles arrived at todays prices, they weren't cheap then, but it was reasonable value if it did what you wished it to do legally, safely and comfortably.

Fast forward to today, what we paid in January 2020, $68,495.00 is now approximately $97,000 AUD plus on road costs and government taxes. This is a 41% increase from the manufacturer, let alone the secondary manufacturers that will be doing the conversions.

Late last year a couple I know received their 2023 manufactured NPS 300, it is a single cab chassis, super singles, tray and some other stuff which set them back $170,000 AUD. Then when they got it home they added their slide-on camper.

Costs of these vehicles, seems to have gone ballistic, but the reality that I see is that most automobile manufacturers have put their vehicle prices up similar amounts to what I've just said, which is somewhere around a 40% price increase.

Mick.
 

gator70

Active member
Even so, the prices in the USA for Revels or Storytellers are $250k US. Just MB sprinter based. And they are far from the Isuzu nps in capability and habitat options
 

gator70

Active member
I have introduced myself before. My current project is based on this thread started 45 days ago. In 2025-2026 I will start a Unimog u300 project. For now I will park that at my sons house in Germany.
 

gator70

Active member
Since we are building out the 4wd for a US 2wd, other folks might want to get data on the process and solutions. We start with 2004 f550 axles. As we want leaf springs. The weight GVWR will be the same. You must buy the NPR HD. We want crawl gears like a unimog to save the transmission, so we go with the dual transfer case adaptor.
 

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gator70

Active member
How low can you crawl with 4:88 axles?

The Adapter kit allows you to mate the reduction box portion of a NP203 transfer case to the stout NP205. The addition of the NP203 range box gives the option to run either transfer case independently in high or low (1:1, 2:1) or to run both in low (2:1 x 2:1) and DOUBLE your reduction for an astounding 4:1 low!
 

DzlToy

Explorer
^^^ this is a common misconception. I have made posts about this previously, but will do so again here for the sake of clarification.

Especially with large vehicles such as NPR/NPS, Mercedes Sprinters with 6" of wheel travel, OKA, MAN TGM, Volvo C303 and the like, basically anything bigger than a Polaris RZR, the ability to crawl, is invaluable. You do not want 5 - 8 tonnes flopping or bouncing around or sliding out of control. You want everything calm, smooth and very controlled, with plenty of time to react if something goes wrong.

There is less stress placed on the drive line, less damage done to the trail, more reaction time provided and fewer white knuckles from your passengers. Many who make comments such as, "I am not rock crawling, so I don't need low gears." have never ridden in or driven a deeply geared truck or buggy. The difference is chalk and cheese.

A Jeep JK Rubicon with a manual transmission has a crawl ratio of 84:1, while a USDM Sprinter has a 'crawl ratio' of about 25:1. I have ridden in Toyota trucks, 4Runners (Surf) and buggies with well over 200:1. It is astonishing what the vehicle will literally crawl over or up, with no effort whatsoever, even without diff locks, throttle input or brakes being used.

In the video below, the incline is quite steep, but I have seen MANY vehicles with "All-Terrain" tires and open diffs get stuck on wet grass, a muddy road or at a water bar running across a trail or track. Please watch the videos linked below and pay close attention to the speaker/host, the conditions and the text on the screen.




Note: this is NOT difficult terrain, yet the truck is hampered by AT tires, poor articulation, open diffs and high gearing. Whaddaya know, it's just like most SUVs, AWD vans and nearly everything this side of a Unimog.




The latter part of this video provides ample evidence for why "off roading" has been given a bad name and in many places, is simply banned. Having owned, driven and ridden in both "types" of vehicles, crawling up obstacles that are impossible to walk up, lots of gearing, slight throttle inputs, controlled and calm are certainly the way to go.


 
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DzlToy

Explorer
To determine the 'factory equivalent' crawl ratio, you have two options.

1) Use an on line calculator that just spits out the answer so long as you enter correct parameters.

2) Do a bit of reading and some math and learn a thing or two.

As I am familiar with Toyota HiLux trucks in the US, I will use them as an example. The formula applies to any truck or SUV that is 4WD.

* First Gear: 3.954:1 * Fifth Gear: 0.85:1

So, you are in first gear, on a gravel road, in 4WD low range. You have a 255/85R16 all-terrain tire and open differentials. As Toyota HiLux trucks use a real, gear-driven transfer case, there is no such thing as a 'center diff' in this example. Front and rear drive shafts spin equally once in 4H or 4L.

This tire turns 610 revs/mile. Factory diffs are often 4.10:1 in these trucks, so we will use that.

You are idling along at 1000 RPM; the clutch is out; you are in 4L. For each revolution of the engine, your tires turn

1000 RPM (divided by) 3.954 (divided by) 2.28 = factory low range transfer case gears (divided by) 4.10 (R/P) = 27 RPM (at the tires)

Crawl Ratio is simply the product of all of the gear reduction: 3.954 x 2.28 x 4.10 = 37:1

Now, if you know the circumference of your tire, you can determine RPM and cruising speeds. In the above example, the HiLux is moving along at a leisurely 2.65 MPH. This is much too fast for technical terrain and will leave you slipping the clutch, bouncing over obstacles or damaging the trail or truck.

Replace the 2.28 gear set with a 4.7 gear set and change the diff from 4.10 to 4.88, whilst keeping your 33" tires, and you are now crawling along at just over 1 MPH. Your total reduction is 90:1, better than any new truck or SUV that I know of. Previously it was 37:1, which is not great by any means.

Let's say you want to cruise at 65 MPH with a 33" tire, but don't know the RPM at that speed. Using some simple math, I see that you will be cruising at about 3200 RPM. Now, let's say you install a 37" tire and 4.88 R/P, but keep everything else the same. Your RPM at a 65 MPH cruise is about 2400. While this may sound better, if the engine does not have the torque to turn 37" tires at this RPM (in fifth gear), you will be running in fourth (higher RPM), drinking fuel, or both.

It isn't rocket surgery to figure all of this out, but most people don't bother. They end up with poor driveability, poor fuel economy, poor off road or on road gearing, frightened passengers or broken parts.
 
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Ultimark

Active member
Two of my nephews have Toyota Hilux Utes, both of them have left their gear ratios as standard, although one of them may change his. Their standard ratio is 32.08 : 1 which reflects that both are running 2.8L diesels. Which may be a reason they are running different ratios to what you are mentioning in the USA.

My very good friend has an Iveco Daily, which is running 24 gears and a final drive ration of 101 : 1, this is stock standard. Although it is a smallish light truck at 5500kg. He runs it around 5450kg; weighed last Saturday. Fully loaded at 5480kg he can and has done a 45º slope, literally idling up; very impressive.

Our NPS as standard has a final drive ration of 54.54 : 1 which is reasonably good for what it is. We are travelling around 5900kg; weighed last Saturday. The NPS is designed for 7500kg and at that weight cannot ascend a 45º slope. But at 5900kg or thereabouts, it does and has ascended a 45º slope. It too idled up in 1st gear low range with the tyres at approximately 1.9 atmospheres pressure. Our final drive ratio is slightly different as we are running 37" tyres compared to the standard 35" tyres, but the torque of the low revving 5.2L Isuzu diesel, seemingly negates the 2" difference.

All of the examples you have shown are with empty vehicles, in the real world, and especially with light trucks, one needs to be able to do things fully loaded because that is how you travel. As for rock crawling, loaded light trucks do struggle, compared to smaller utes like the Toyota Hilux and similar. But load a Hilux ute up and watch them struggle as the loaded light truck mostly idles past them.

We have driven over lava flows, which required very, very slow speed. In low range first gear it is just slow enough for the truck to idle over the very uneven rocky terrain.

In Australia the NPR has a final drive ratio of 24.90 : 1, The NPS has a final drive ratio of 54.54 : 1.

Interesting videos, thanks for the links.

Mick.
 

rruff

Explorer
How lucky....here in Spain you can't move a single screw without an engineer involved.
I do very very much appreciate sanity in the US when it comes to vehicle mods. It's one of the last enclaves for it...

But I'm sure it will end before long, with many on this forum supporting its demise...
 

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