It’s a shifty business. Looking for a new or pre-loved 4WD is a chance to choose which fuel, which engine, and which transmission best suits the planned use of that vehicle.
But this month, we home in on which transmission works best for on and off-road driving.
Leave aside manual transmissions, because the vehicles offering manual shifting are few and becoming fewer. That’s a bit sad for drivers who like the greater engagement and control offered by a manual, but it’s been coming for a couple of decades.
The difference between manual and automatic is simple. A manual has a set number of gears, and the driver determines what gear ratio they need. An automatic also has a set number of gears, but it uses a hydraulic system that responds to pressure created by the conditions to determine the gear needed without any input from the driver.
CVT stands for Continuously Variable Transmission. It has flexible belts on pulleys that can change their width to seamlessly provide drive at different speeds while keeping the engine in its ideal rev range for its torque and power profiles.
This means a CVT works well in urban going and can even come with fuel economy benefits.
American car magazine Car and Driver says “depending on the vehicle and the driver, a CVT can provide a smoother driving experience when comparing it to a traditional automatic. According to Carfax, one of the most significant advantages to having a CVT is that they are often more fuel-efficient than a regular automatic.”
Not all CVTs are created the same. The most common type is the pulley-based, but some other types include the Toroidal CVT, which uses rotating discs along with power rollers to produce the same result as the pulleys. The hydrostatic CVT uses pumps to control fluid flow, which then produces a rotational motion.
But translate that into an off-highway drive and it’s apparent a torque converter auto is the preferred weapon. One of the big issues with CVT is its difficulty shedding heat generated as the belts flex and rub against the pulleys. All transmissions create heat, but a torque converter transmission use fluid in order to function. That fluid is pumped through the transmission, which in turn simplifies cooling, enabling the transmission to send its fluid out through an external oil cooler and back into the transmission.
Likewise for towing. Harder work means more heat.
Nissan’s immensely capable Pathfinder had an awkward transition to CVT a few years back and many prospective buyers who used the SUV for towing migrated to other SUVs with ‘proper’ auto transmissions. Nissan was listening: the current Pathfinder is back to a torque converter transmission.
So which auto? With Ford (and Volkswagen) using a ten-speed auto at one end of the scale and the likes of Isuzu running six speed units, what’s the ‘sweet spot’?
Transmissions with more ratios cope with narrow torque bands, while engines with a fatter maximum torque zone like the Isuzu can use less ratios.
However, having driven many utes and SUVs with eight speed auto transmissions over the past year, NZ4WD is convinced that ‘eight is enough’. More ratio options than a six speed; not as many shifts as a ten-speed. The latter means there’s less tendency to ‘hunt’ between ratios, which important in twisty or choppy going.
Who agrees? BMW, Chevrolet, Dodge, Ford, Ineos, JAC, Jaguar Land Rover, Jeep, LDV, Nissan, Toyota, Ram, and many more.

Image courtesy BMW