Turbodiesel heroes you might have forgotten about

Before turbopetrols became all the rage, turbodiesel engines were favoured for providing torquey, yet fuel-frugal performance in passenger cars – diesel derivatives were often the top picks of their ranges. We pay homage to the turbodiesel heroes.

To mangle a metaphor: if no one is a prophet in their land, then there’s no better example of the fate of the turbodiesel-powered car over the years – first in Germany, then greater Europe, the United States and ultimately – globally.

*Audi built a roadgoing version of its Le Mans-winning 6.0-litre V12 turbodiesel into its 1st-gen Q7.*

After more than a century’s refinement, Rudolf Diesel’s process of mixing compressed air with recirculated exhaust gases turned turbodiesel engines into the torquiest and most economical of their type, owing to higher thermal efficiency (and each droplet of fuel having a higher energy density) than their petrol equivalents.

Diesel’s only drawback then, as it remains today – apart from an extremely narrow torque band – was only ever emissions control. The rise and fall of the VW Group’s desire to dominate the world’s diesel car market by eschewing the diesel emissions-killing AdBlue additive and fitting emissions-masking “defeat devices” to some of its models is well-documented. That’s why, in the aftermath of “Dieselgate”, myriad turbodiesel model designations – offered by a multitude of car brands – have thinned out dramatically.

‘Dieselgate’ destined turbodiesel cars for extinction

Before September 2015 (when “Dieselgate” was exposed), the automotive world was a better (and ignorantly happier) place. On one end of the scale, turbodiesel engines had transformed so-equipped hatchbacks into hypermilers. And on the other, it created a class of tar-shredding super-sleeper sedans.

Students could be sent off to university in a Ford Figo 1.4- or 1.5 TDCi, or a Fiesta 1.5- or 1.6 TDCi (if you lived on the right side of the railway line). The problem for car company product planners, though, was that for all their appeal, turbodiesel engines were (and are) more expensive to produce than petrol ones.

All of this meant that diesel derivatives that played in the cut-throat genre of affordable hatchbacks had to be specced to the level of entry-level variants to bear any semblance of price competitiveness.

Turbodiesels ‘de-specced to be more affordable’

Consequently, the Ford Figo turbodiesel was only available in Ambiente trim, which in the Blue Oval’s parlance is about as luxurious as a mobile SASSA cash payout office.

Ditto the Fiesta turbodiesel, whose line-up admittedly also sported a pricier Trend version, yet the latter still languished as laughably under-equipped against the petrol-powered Titanium or superb ST flagship.

Unsurprisingly, Volkswagen offered a variety of turbodiesels in its Polo range, including the 1.2-, 1.4-, 1.5-, 1.6- and 1.9 TDI. Even if punchier than their petrol counterparts, they were notably pricier when similarly specified. I recall that in 2014, you could have the 1.2 TDI Bluemotion, yet it was so spartanly specced that you’d have been grateful for merely receiving a body and 4 wheels; or a somewhat pricier 1.6 Comfortline that at least additionally netted you a spare wheel (well, in a manner of speaking).

Search for a used turbodiesel-powered Volkswagen Polo

Up a category in Golf-land, things weren’t rosy either. If you were after a Golf 2.0TDI Highline for Mom, you might as well have made the R23k stretch and bought a GTI, especially if it was being financed. Yes, there was the 2.0TDI Comfortline, but you’d have been lucky if it came with anything more than a radio.

The Wolfsburg-based brand also introduced the closest thing to a turbodiesel hot hatchback when the Golf GTD debuted as part of the “7.5” update in 2017; when reviewing the GTD, we found it refined and frugal, but unable to match the excitement of its GTI turbopetrol sibling. Watch or read our GTD review.

One would never dream of equating bread-and-butter Japanese family cars with hen’s teeth, but Honda and Toyota used to sell turbodiesel variants of the Civic and Corolla, but they were underappreciated.

Instead, the Aichi-based manufacturer focused on its commercial turbodiesels that powered everything from the Hilux to Land Cruiser 70 -series and the Fortuner to the Land Cruiser 200 and -300 SUVs.

Meanwhile, when the compact family car segment rose to prominence about a decade or so ago, the pioneering Renault Duster and Ford EcoSport fielded turbodiesel variants; such was the success of the former’s diesel motor that the outgoing version of the Duster is available exclusively in turbodiesel guise!

Search for a new/used turbodiesel Duster | Search for a used turbodiesel EcoSport

There were few other turbodiesels to speak of in this segment… You could have a diesel-sipping Nissan Juke, but only in premium economy Acenta+ grade – all the model’s fancy features were heaped into the GT and Tekna specifications. Kia, however, remains a notable champion of Rudolf Diesel’s creation – it offers a 1.5-litre 4-cylinder turbodiesel, with a claimed fuel consumption of 5.5 L/100 km, in the Seltos.

See also: Kia Seltos (2024) Launch Review

An antidote to breathless ‘atmo’ petrol engines

Perhaps Hyundai Kia had the European market in mind when it offered punchy 2.0-litre turbodiesel engines in the Tucson/iX35 and Sportage ranges, but we were grateful nonetheless. In the 3rd-gen iterations of those models, the 130 kW/383-393 Nm CRDi lump offered notably more pep than its 2.0- (122 kW/197 kW) and 2.4-litre (130 kW/227 Nm) naturally aspirated petrol-powered counterparts, which – not to be too unkind – needed to be whipped into a froth to summon urgent overtaking acceleration.

See also: Our Buyer’s Guides for Hyundai ix35 (2010-2016) and Kia Sportage (2010-2016)

To the Korean giant’s credit, it still offers turbodiesel powerplants in its Tucson and Sportage line-ups; The Toyota RAV4 and Mazda CX-5 were available in diesel guise, but alas, no longer are. And, I hardly need to say it: Volkswagen still offers a Tiguan 2.0 TDI… and the next Tiguan will again offer a diesel.

Search for a new/used turbodiesel Hyundai Tuscon, Kia Sportage or Volkswagen Tiguan.

SUV land is still turbodiesel country

As for any passenger car bigger than a family car/medium SUV, you are still likely to see turbodiesel engines on duty until they are voluntarily phased out by their makers – or legislated out of existence.

While there are some exceptions, such as the Ford-engineered 4.4-litre V8 turbodiesel in the larger Range Rover models, or the British brand’s newer mild-hybrid 3.0-litre inline-6 Ingenuim motor (as found in the Range Rover Sport D350 Autobiography), the true protagonists of turbodiesel propulsion, at least as far as luxury passenger cars are concerned, have been Audi, BMW and, to an extent, Mercedes-Benz.

*To demonstrate the might of the Touareg 5.0 V10 TDI, Volkswagen made it tow a Boeing 747-200 weighing about 155 tonnes.*

The Volkswagen Group, which was a rather cavalier multinational in the Noughties, took the turbodiesel genre from the sublime to the ridiculous when it launched the 1st-gen Touareg with a 5.0-litre V10 TDI that produced 230 kW/750 Nm and 1st-gen Audi Q7 6.0 V12 TDI that produced 368 kW/1 000 Nm. The latter, of which only a handful were imported into Mzansi, was said to blast from 0 to 100 kph in 5.5 sec.

BMW produced middle-management missiles such as BMW’s fabulous 330d to the thunderous 535d with 230 kW and 630 Nm (which eclipsed the F10-gen M5 in every respect other than dynamic ability).

See also: BMW 330d (2016) Review

The Bavarian marque’s twin- and tri-turbodiesel mills turned everything we thought we knew about performance engines on its head – they transformed steep torque curves into plateaus that made for eye-blinkingly rapid overtaking without the need to drop a gear, all with sane fuel economy to boot.

Following that spectacular Teutonic flex that was the Q7 6.0 V12 TDI, Audi applied its years of experience of winning the 24 Hours of Le Mans with diesel-powered engines to produce my favourite TDI engine of the era – the 230 kW/650 Nm bi-turbo 3.0-litre V6. It was wedged into the engine bay of the SQ5 and A7 and coupled with all-wheel-drive, transformed both into reluctant hot-hatch humiliators off the line.

See also: Audi SQ5 quattro (2017) Review

The sequential turbochargers were asynchronously sized so that once the (significant in its own right) torque peak plateaued, the 2nd turbocharger kicked in to deliver peak power over another band of 600 rpm, which was unusual, but devastatingly effective. Best of all? It sounded like Zeus with a sore tooth.

For those who may have found that motor too, um, weedy, the SQ8 – though powered by a 4.0-litre twin-turbo V8 petrol engine since its facelift – used to be powered by a turbodiesel of the same capacity, cylinder- and turbo configuration. We reviewed the 310 kW/900 Nm SQ8 in 2021 – it was a powerhouse.

Search for a new/used turbodiesel Audi listed on Cars.co.za

Is the Quad Turbo the ultimate turbodiesel hero?

But BMW was not to be outdone by its rival based in Ingolstadt (and the latter’s Audi Sport division in Neckarsulm). In 2016, the Munich marque launched the 3.0-litre, inline-6-cylinder B57D30S0 engine that featured – wait for it – a quartet of turbochargers, for service in the X5-, X6- and X7 M50d variants.

Watch Ciro De Siena’s video review of the BMW X5 M50d:

See also: BMW X7 M50d (2019) Review

This meant that without gaining engine capacity or sprouting more cylinders, BMW’s apex turbodiesel-powered, 2.5-tonne premium SUVs could defy physics by their abilities to rocket from 0-100 kph in about 5 seconds, while still being capable of delivering 7 L/100 km and travelling 1 000 km on a single tank.

The timing of its arrival was all wrong, though. Post-Dieselgate, as far as the passenger-car market was concerned, anything to do with diesel became, in a word, dirty – which made it convenient for BMW to drop the expensive, über-niche B57D30S0 in September 2020 to instead focus on an electric future.

See also: BMW X6 M50d (2020) Review

Search for a new/used turbodiesel BMW listed on Cars.co.za

Besides, Dieselgate and its ramifications aren’t solely to blame for the demise of turbodiesel-powered passenger cars. Turbopetrols are now well entrenched and favoured by product planners and car buyers.

It does need to be mentioned that many of the turbodiesel heroes listed in this column are still likely to be pricier to service and maintain than their petrol contemporaries… Their fuel and lubrication systems need more regular attention by comparison and their emissions-reducing components (such as exhaust gas recirculation- and diesel particulate filter systems) tend to cause separate headaches as the cars age.

*In 2002, Mercedes-Benz produced a C30 CDI AMG with a 3.0-litre 5-cylinder turbodiesel (170 kW/540 Nm).*

Celebrate our (fallen) turbodiesel heroes

Sadly, the world will probably never see a high-performance turbodiesel motor in a road car again. It rapidly became the forbidden fruit of going fast – one that we will, one day, tell our astonished grandkids about. Little known even in petrolhead circles, today such talk only exists as if in fairytales: “I am legend.”

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