Isuzu FTS vs FSS for Project Grambo.

[Hoff]

Hi guys,

I’m in the process of looking for an Isuzu FTS or FSS crew cab truck to build a semi off-road camper for my family of six.

I’ve had to go the F series due to the fact the NPS 75/155 crew just doesn’t have the tray length and GCM I need.

All I can see regarding the difference between the FTS and the FSS is the FTS is a 7.8l 6 cylinder with 236hp/176kw and the FSS a 5.2l 4 cylinder with 202hp/151kw, plus the FTS comes optioned with the Allison auto.
Is this the only difference between the models?

I’ve found a tidy 2008 FSS with only 100,000km on the clock but just want to make sure I’m not leaving myself underpowered as I also wish to tow a good sized (6-8m) boat down the track, but looking at the power figures and given the 2 litres extra displacement the FTS has the FSS looks like it’s pulling pretty good power from its 4 banger.

Anyway any info on the subject would be nice and I’m looking forward to documenting the build once I get a truck to start with.

Cheers Hoff

 

[sae8425]

Hoff –

Towing discussions, at least on American internet forums, are heavy on controversy and opinions, but light on facts and science.

Full disclosure: I live in a country where towing over 14,000 Kg with a pickup truck is almost considered to be a constitutional right.


The 2013 FRR (with the 5.2L diesel @ 202 Hp + 5.125:1 gearing) is rated at:

GVM: 10,400 Kg

GCM: 16,000 Kg

Max Trailer: 10,000 Kg

http://www.isuzu.co.nz/specsheet/FRD500 (AMT option available).pdf


The 2016 FSS (with the 5.2L diesel @ 210 hp + 6.5:1 gearing) is rated at

GVM: 11,000 Kg

GCM: 16,000 Kg

Max Trailer: 9,000 Kg

https://www.blackwellsisuzu.co.nz/i/files/FSeries/FSS550.pdf


This is yet another glaring example of the patent idiocy of factory towing ratings!

American accepted practice is to subtract the ACTUAL vehicle weight from the GCM to determine the maximum towing weight.

Yet in the examples above Isuzu is NOT using the ACTUAL vehicle weight to calculate the maximum towing weight. YTFN? Beats me!

Do the laws of physics not apply to Isuzu? Or do American truck manufacturers disregard physics when publishing towing ratings?

In America there are SAE towing standards, federal guidelines, regulations in 50 states, and yes, constitutional implications.

Numerous NPR owners in America have commented on forums that Isuzu USA has told them the NPR 3.9L towing rating is 2,722 Kg.

All other towing factors being remotely similar, the golden rule of towing is: there is NO replacement for DISPLACEMENT!

More torque + more gears + deeper ratios (10:1 1st gear + 6:1 axle is MUCH better than 5:1 1st gear + 4:1 axle) = better towing.

Yet I'm currently considering buying a 2006 NQR crew cab which will (occasionally) tow somewhat more than 10,000 kg. Go figure!

But I would upgrade this NQR to make it into a MUCH more capable towing vehicle (bigger brakes, deeper gearing, tuning, etc.).