Constant velocity in a Datsun Go

CVTs have a bad reputation, especially amongst motoring journalists. But, surprisingly enough, the mix of a “gearless” gearbox and the Datsun’s little 1,2-litre 3-cylinder motor made for no-hassle motoring over December and January in Johannesburg.

I must admit that I wasn’t really looking forward to spending a month with a CVT version of the Datsun Go. This new two-pedal version of the Go was launched in early November 2019, and, while the driving experience during that launch event impressed me with the big advances in terms of overall feel, ride quality and highway stability, I was still convinced that the typical limitations of a CVT gearbox would start to get on my nerves by the end of the holiday season.

What is a CVT gearbox?

The term “CVT” stands for “Constantly  Variable Transmission”. This type of gearbox initially made its appearance in a quirky little Dutch car introduced in the late-1950s, called the DAF. The basic idea behind the transmission is to keep the engine in its optimal torque range, the whole time the car is on the move.

How does a CVT work?

The CVT gearbox essentially consists of two variable-diameter (conical-shaped) pulleys, linked by a steel belt or chain. According to power and torque demands, dictated by the position of the accelerator pedal and engine speed, the positions of both the input- and driven cones are altered to effectively change the ratio without any steps, unlike you would get with a conventional manual gear transmission or a fluid-drive conventional automatic transmission.

More lately, manufacturers have introduced artificial “steps” in the way the belt or chain moves between the two variable diameter pulley-cones. These steps can often be controlled by a paddle shift system.

Does the Datsun Go CVT have paddle shifts?

The Datsun Go CVT does not feature paddle shifters or “steps” to simulate gear changes, presumably to keep costs down – this is still an entry-level car, after all. What the Go does have is a “low range” position on the console-mounted gear selector. This limits the speed range of the CVT gearbox, but allows you to operate the car in a very limited low-speed range from idle engine revolutions to maximum revs (and boosts engine braking when coming off the throttle).  I never encountered a situation where I needed to use the low range option at all, though.

Why do so many motoring journalists criticise CVT gearboxes?

Motoring journalists are trained to focus on the more subtle aspects of automotive performance. One of the annoying characteristics of many CVT systems is that they tend to induce a droning effect from the engine, as it operates at a constant speed regardless of road speed. This typically occurs when hauling up long hills on a freeway. The car’s engine note with a CVT gearbox remains at a fixed pitch even when speed increases, because this is the way a CVT is designed: to keep the engine operating in an optimal rev range as speed increases or decreases.

What this effectively means is that the engine takes on a single-pitch droning note for long periods with no relief. Manufacturers have become aware of this negative CVT factor, and have introduced artificial steps in the operation that simulate the gear changes you would typically get with a more conventional automatic transmission.

 

Does the Datsun Go’s CVT become irritating?

Surprisingly, the Datsun Go’s CVT gearbox comes close to avoiding that irritating drone factor. If you accelerate hard from standstill, the engine quickly reaches its peak power range at around 5 000 rpm, and it will hold this for as long as you keep your foot flat on the accelerator.

But if you lift off the accelerator even slightly, the revs drop substantially without too much in the way of lost acceleration. To then increase speed, the trick with the Datsun CVT is to gradually increase pressure on the accelerator pedal. It then builds speed at a much lower rev range, at around the 3 000 rpm mark. After a while, driving the Go like this becomes natural.

 

What about economy?

As it so happens, a year ago I had a Datsun Go five-speed manual for test, also during the holiday period in Johannesburg. The low-volume traffic situation I experienced a year ago was almost identical to what I experienced between early December and early January, over the 2019-2020 change-over to the new decade. However, although Datsun claimed (in its November 2019 media release) that the CVT automatic offered “better power delivery and improved fuel economy when compared to traditional transmissions”, this is definitely not the case.

During a mix of mainly urban driving, including plenty of gradients around my home terrain (in Randburg) and a number of highway trips to the airport and to Pretoria, I ended up with an overall fuel consumption of just under 7,0 litres/100 km. This compares to the consumption I achieved with the five-speed manual Go a year ago (the engines are virtually identical, although the Go CVT engine has slightly more power) of 5,7 litres/100 km over the same period.

Here is a direct quote from my January 2019 report in AutoTrader: “To achieve 5,27 litres/100 km I had to shift up to a higher gear at 2000 rpm in every gear. I had to keep my highway speeds down to around 110 km/h, except on the downhills.” In other words I had to work at achieving that low figure. But I worked at low consumption on the CVT version too!

 

It’s much more difficult to save fuel in a car equipped with a CVT transmission.

With the CVT, you don’t have nearly as many options to keep the revs down whenever you can. In a manual, you can shift up to higher gears as quickly as possible and, as we all know, lower revs (in a higher gear) means better fuel consumption. But when faced with pulling off from a stop on a longish uphill gradient with the CVT, that engine is going to be revving harder every time. You can’t “ease” the revs up on a light throttle opening so you can select a higher, more economical gear so easily. If you try it, even during holiday time in Jo’burg, the people backing up behind you start hooting!

On a level road, however, with Datsun’s CVT, you can keep those revs down, as mentioned earlier. But the slightest change in gradient (leading to an uphill climb) means that the revs are going to climb in response to increased accelerator pedal pressure, to the detriment of fuel consumption.

 

Did the CVT gearbox spoil my time with the Datsun Go?

Funnily enough, apart from the higher fuel consumption, I quite enjoyed the absolutely fuss-free nature of the CVT. You slot home drive mode on the gear lever, and then forget about anything else until you stop, select Park, and switch off. Even on the highway and on uphills it wasn’t as intrusive as I thought it would be, although I tended to keep my cruise range closer to 110 km/h than 120, except on long flat sections and downhills.

 

The ride in general

As mentioned in the launch report from late 2019, the Go has been transformed by the addition of a new roof structure and reinforcement to the doors, as well as increased sound-deadening. The whole car feels much more solid now, right from the moment of engine start-up. The slight shudder through the body-shell from the three-cylinder engine didn’t made their way to the cabin, either.

On the road, through both suburbs and on the highway, the feeling of increased solidity is maintained. The directional stability has been improved on the highway, and on bumpy suburban streets ravaged by summer storms, the ride is far more composed than before. Bump absorption over bigger bumps remains excellent, as has always been the case with the Datsun Go.

Quirks?

There are one or two quirks. The luggage compartment cover isn’t suspended by draw strings, so you have to flip it up when you are loading stuff in the boot. Then, because it is black plastic, you sometimes forget it raised, and when you hop in and then look out the central rear view mirror, there is no view! It took me a while to remember this and flip the security flap down before closing the boot lid.

The material covering the seats looks smart, but it is actually not as durable as it looks. After a day spent standing in the hot sun the rear seat cover developed a bit of a wrinkle, which doesn’t bode well for it lasting blemish-free over years to come! The other factor you have to remember with the Datsun Go CVT model is that initial pull-off from standstill on an uphill is not that quick, so you have to consider this if you are going to attempt a quick dart across traffic. Rule of thumb here: wait until it’s all clear!

 

Overall verdict

I could quite easily live with the Datsun Go in its latest guise. It has a feisty little engine that is more than up to the task, economy is pretty good (I would go with the manual model, which also features all the latest updates in terms of body-shell rigidity etc), and I still prefer it to the comparable Renault Kwid by a long chalk. Looks-wise, those new style alloy wheels on the Lux model have also made it look much more funky than before, and inside it has a crisp infotainment system that brings it nicely into the modern era. Even the dashboard finishes are smart-looking.

The Datsun Go Lux CVT is priced at R188 300 (cheap cars are no longer so cheap!). I would opt for the Go Lux 5-speed manual at R173 600. Even though its engine is rated at only 50 kW compared to the 57 kW of the Auto (CVT) model, overall you still get more punchy performance and much better fuel economy with the manual. There again, if I had to do a daily commute through many kms of traffic, the CVT model would probably start to make more sense.

 

 

Source reference: https://www.autotrader.co.za

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