Car Tech

The Pros and Cons of Owning a Diesel Vehicle

Limited though they may be, there really isn’t a better time to buy a diesel-powered vehicle.

Those with glass-half-empty outlooks might view the scrutiny around compression-ignition engines as a negative, but the more optimistic among us – your humble author included – will see it as proof that the ones available today are better than they’ve ever been. But just like anything in life, there are at least a few considerations to make before switching to diesel.

1. Can’t Shake the Stigma

There’s long been a stigma around diesel engines, and it predates Dieselgate – though the Volkswagen Group’s scandal certainly hasn’t helped them catch on in this part of the world. Plenty of folks think of diesels as loud, soot-spewing tractor engines, and all those coal-rolling diesel bros definitely aren’t doing much to end that anytime soon.

But the reality is that diesels can be pretty quiet – especially modern ones like the 3.0L that’s available in the GMC Sierra 1500 (and its Chevrolet Silverado twin). There’s still a bit of familiar clatter at idle and through initial throttle tip-in, but it’s nothing like it used to be.

2. A Few Added Expenses

The extra upfront cost that usually comes with picking a compression-ignition engine isn’t the only added expense to consider, with a few other more marginal increases to keep in mind. For starters, diesel fuel tends to be a bit pricier at the pumps compared to regular-grade gasoline. Routine maintenance like oil changes also tend to cost a bit more compared to conventional gas engines.

Then there’s the added expense – and inconvenience – of filling modern diesel-powered vehicles with the requisite diesel exhaust fluid (DEF). Since diesel engines produce more nitrogen oxide than their gas-powered counterparts, urea-based DEF is sprayed into the exhaust system to convert the pollutants into nitrogen and water. However, it’s about as easy to top up as washer fluid, and a $20 jug should last at least a few thousand kilometres.

3. It’s Not Offered Everywhere

While diesel is by no means as difficult to come by as hydrogen fuel, not every gas station has it. While diesels generally offer outstanding driving range between fill-ups, there’s nothing worse than coasting into a station only to find out diesel isn’t sold there – especially if it’s on a lonely stretch of highway, with the next station hundreds of kilometres away.

4. Cold-Start Calamity

Modern diesel engines have been improved over their predecessors in plenty of different ways, though not all issues can be completely eliminated. Take diesel fuel’s reaction to cold, for example; since it’s prone to gelling as temperatures fall, these engines can have trouble starting during winter months. That’s where the glow plugs come in, warming the air and fuel needed to start the engine in the first place. While warm-up times have dropped significantly over the years, Canadians may notice it takes a little longer to start a diesel engine during a deep freeze.

5. Tons of Torque

Minor inconveniences aside, one of the big benefits of buying a diesel is all the low-end torque it comes with. While horsepower is generally less than an equivalent gas-burning engine, torque is usually way up. Take my own 2014 Volkswagen Golf TDI wagon: output stands at a meagre 140 hp compared to the gas version’s 170 hp, but the torque count is 236 lb-ft versus 177 lb-ft. Best of all, maximum torque kicks in at just 1,750 rpm, resulting in surprisingly swift acceleration. Early torque delivery also helps with towing and hauling, and that’s a big reason diesels have long been popular in heavy-duty pickup trucks.

It’s worth noting that modern turbocharged gas engines deliver torque at incredibly low engine speeds, too, but they just can’t compete with their diesel-fired counterparts. Driving is believing, and the earth-moving force of a diesel is truly something to behold.

6. Outstanding Efficiency

The additional costs associated with diesel ownership may add up – and they may take years to offset through savings at the pump. But there’s something especially rewarding about driving 1,000 km or more between fill-ups and averaging better-than-hybrid fuel consumption while doing it.

The combined average of my personal car – granted, with a highway bias – is consistently around 4.6 L/100 km, which is better than some conventional hybrids, and way better than just about any gas-powered car I can think of. Even the diesel-powered Sierra 1500 burned just 9.7 L/100 km over the course of a week of testing, which is ridiculously low for a full-size truck.

They may be few and far between, but there are plenty of reasons compression-ignition engines are better than they’ve ever been. Diesel never caught on here like it did in other parts of the world, but now more than ever, it’s worth looking into for your next purchase.