BUYERS GUIDE - UTES & CAB CHASSIS LARGE
Released in mid-2018 the GMSV-modified Chevrolet Silverado 2500 range comes with truck-diesel grunt.
The Silverado 2500 range is at variance with the accepted US nomenclature for pickups: a ‘1500’ has around 1500 pounds (700kg) payload capacity, including people and fuel; a ‘2500’ has around 2500 pounds (1100kg) payload capacity and a ‘3500’ has 3500 pounds (1600kg) payload.
However, the Silverado 2500 has less than the Australian-FBT-critical one-tonne payload capacity, between 875kg and 975kg. but towing capacity is up to 5.89 tonnes.
All crew cab vehicles in this range have the same powertrain: an Isuzu-developed Duramax 6.6-litre turbo-intercooled diesel V8 engine that pumps out a maximum 332kW of power and 1234Nm of torque and is mated to an Allison 1000 six-speed automatic transmission.
Four-wheel ABS disc brakes and an automatic locking rear differential are standard.
Suspension is by torsion-bar sprung wishbones up front and leaf-spring rear axle.
Wheelbase is 3904mm; cargo box length is two metres and width, 1586mm.
Fuel tank capacity is 136 litres and there’s also an AdBlue tank for the emissions system that incorporates cooled exhaust gas recirculation (EGR), diesel particulate filter (DPF)and AdBlue urea (SCR) NOx catalyst.
The base-model WT is well specified and is keenly priced in this US-import market section at $114,990.
Standard equipment includes: truck-type exhaust brake; transmission oil cooler; traction control; stability control and trailer sway control; frontal and side SRS airbags; manual tilt steering column; cruise control; tow bar; trailer brake control; rear view camera; 3.5-inch display; single-zone aircon; remote keyless entry and 40:20:40 folding rear seat.
At a RRP of $134,990 the black or white LTZ versions add: digital steering assist; manual tilt and telescoping steering column; power-adjustable pedals; heated, leather-wrapped steering wheel rim; auto-dimming rear vision mirror; front and rear park assist; 8.0-inch display; floor console; hill descent control; underbody rock shields; dual-zone aircon; heated and vented, leather-faced, power-adjustable front seats; garage door opener; powered, sliding rear window; 60:40 folding rear seat; rear under-seat storage and a BOSE sound system.
But the Silverado 2500 has a weight problem, tipping the scales at a hefty 3516-3616kg dry and empty, with a GVM of 4491kg, just under the passenger car licence GVM-ceiling.
That tare weight is a result of fitting a powerful, heavy engine with torque way in excess of the amount needed to tow typical heavy caravans and trailers in Australia. That grunt also necessitates a truck-type automatic transmission, with chassis, driveline and axle strength to match.
The weight problem starts at the pointy end, where the Duramax plus Allison powertrain combination is around twice the weight of a US-market petrol V8 plus auto box. Not helping the weight issue is complex intercooler and turbo plumbing and an emissions system that has the full suite: DOC, DPF and SCR.
Interestingly, GM developed a lighter, 4.5-litre version of the Duramax 6.6-litre diesel, but it never went into production: presumably because of the general disaffection with diesels in the USA, post VW’s ‘dieselgate’ scandal.
On and off road
Our road test Silverado was a ‘Midnight Edition’ 2500LTZ model that proved to be one of the most enigmatic test vehicles we’ve ever had. On the plus side were enormous grunt with good economy from the Duramax diesel, high specification levels and good fit and finish, but the negatives were minimal payload
capacity, poor frontal and side vision, vague steering and weak suspension damping.
Wheeling the big Silverado out of the Suttons carpark and through downtown Sydney was something of a handful, thanks to a high bonnet line that ran without downslope to the front of the vehicle and a fat passenger-side windscreen pillar and rear vision mirror mount that reduced left-side frontal view. (I test heavy trucks in my other life, so I’m well used to road-train-size gear.)
On top of those issues was less than precise steering, with a ‘dead’ spot in the middle of the wheel movement.
Ride quality was OK on smooth surfaces, but the leaf-sprung rear end hated lumpy bitumen and gravel, leaping about on bumps and potholes.
For some weird reason the much-vaunted Z71 suspension kit featured Rancho twin-tube 35mm-diameter-piston shock absorbers that our previous suspension testing shows aren’t real flash at controlling lightweight 4WD axle bump and rebound, so they were way out of their league trying to settle down the Silverado’s heavy duty back end. The Z71 code used to dial up Bilstein shocks and we suggest GM goes back to that supplier.
The LTZ’s 35mm shocker size is made even stranger by the fact that the base-model WT Silverado comes with 51mm shocks! The WT model also sits on taller 70-profile tyres, not the 275/65 low profiles fitted to the Midnight Edition model that needed way too much pressure to handle 4491kg GVM: the low-pressure warning lit up at 50psi!
Only when we hit the freeway did the big Chevvy feel at home, loping along with hardly any revs on the tacho and fuel economy around 11L/100km. Our overall economy for this test worked out at a relatively frugal 12.6L/100km, including a towing stint with a three-tonnes plant trailer that saw economy at a very good 18.6L/100km.
A note on this economy is that we drove the Silverado like it was our own, but a couple of forays into the ‘red-mist’ zone saw consumption plunge to 30L/100km, so you get, literally, what you pay for!
The Yanks know all about building a tow vehicle and the Silverado didn’t disappoint: massive towbar; manually controllable transmission with exhaust-brake enhanced engine braking; powerful all-disc braking; inbuilt trailer brake control and electronic sway control.
However, the poorly-damped, leaf sprung rear suspension hated our rough dirt road stretch, while low-slung side steps and loaded 230mm ground clearance greatly limited our off-road testing. We were also terrified by the prospect of denting the fat aluminium propshaft that hung precariously low where it joined the rear diff.
As presented, the Silverado 2500LTZ made a powerful, frugal towing vehicle, but it preferred smooth surfaces to the rough stuff. We felt it was under-tyred for its GVM and lacked off-road ground clearance.