Review: Land Rover Discovery Si4
How does the Discovery fare with a four-cylinder petrol engine under its bonnet?
If you were asked to guess what sort of fuel most Land Rovers ran on these days, chances are you would almost certainly say ‘diesel’. And why not: diesel engines have traditionally provided a Land Rover-friendly mix of economy and low-rpm torque.
To many, therefore, the presence of a small turbo petrol engine in the latest Discovery might seem about as welcome as the proverbial gaseous emission in a spacesuit.
What seems to have happened is that manufacturers have become deeply fearful of the diesel witch-hunt. The days of the diesel-powered Porsche are apparently numbered, while other JLR rivals like Audi, Mercedes and BMW are trying to get us interested in electric vehicles until such time as they can properly distance themselves from diesel’s ‘persona non grata’ status.
Anyway, whether any of that is true or not, the evidence of diesel’s new status even in the largely petrol-free domain of large SUVs is here in the familiar shape of this 2.0-litre turbo petrol four Discovery.
We’ve already tried this engine in both the Jaguar F-Type and the new Range Rover Velar, and have enjoyed its refinement and punch each time. Two more plus points of its use here is that it promises to equal the bigger TD6 V6 diesel on performance, and it lowers the entry price of Discovery ownership.
It’s not the only petrol Discovery, mind. At the other end of the range you can get a 3.0-litre supercharged V6, but despite the stats showing that to be the quickest Disco, we found the 3.0 petrol rather disappointing and not as easy to wield as the less powerful but gruntier V6 diesel.
Fortunately, the smaller four-cylinder is not hamstrung by any shortage of usability because its peak torque comes in at just 1500rpm (against 3500rpm on the petrol V6). It actually shifts with surprising alacrity considering the fact that it still weighs more than two tonnes. It doesn’t sound that great, but it’s not annoying and there’s plenty of consolation in the brisk 7.7-second 0-62mph time.
There is a fairly major downside though: fuel economy. If you load it up for a trip and then check your mpg numbers, you’ll think you’ve either gone back to the 1980s or your calculator has blown a gasket. We reckon you could quite easily dip into the high teens. Land Rover claims 29.4mpg is doable, but even that’s not exactly sparkling. On our mixed test route we couldn’t get much more than 25mpg. Blame the shed-like aerodynamics, but whatever is to blame, the bottom line will be a large fuel bill on long journeys – the sort of thing this type of vehicle should excel at.
It’s not unusual for Discoverys though. We’re running a Discovery TD6 on long-term and we hardly ever see better than 26mpg on the trip meter, even though Land Rover says it should return 39.2mpg. So in the Discovery context at least, the Si4 isn’t that bad. It’s also slightly less nose-heavy than the diesel versions, which endows it with a little extra pointiness in bends. It’s all relative of course. Try hard down a B-road and it won’t be long before you return to a gentler and more comfortable pace.
Interestingly, the Si4’s standard 19-inch wheels don’t deliver a better ride than the one you get in a Discovery on optional 22-inch alloys, possibly because JLR is tuning its vehicles to work well on bigger wheels, which is a more enlightened approach given the buying public’s fascination with large wheels.
Whatever wheels it’s on, and whatever size you or your passengers may be, the Discovery remains an immensely practical SUV. It has oodles of head and leg room, not just in the front but especially in the back where there seems to be unlimited width and where no transmission interferes with your foot space. Things are just as impressive in the third row, thanks to the Discovery being designed from the outset as a proper seven seater. Not only will two adults be quite happy there, they’ll even have soft pads beneath the rear windows to rest their arms on. Eeeh, luxury.
All-round visibility is excellent, although we’d prefer the reversing camera to be standard, as the parking sensors are. We’d also prefer better access to the infotainment system that that provided by the less than intuitive ten-inch touchscreen. The patchy interior quality grates a bit too.
Still, it’s good to find just how well this turbo four petrol motor works in the Discovery. Don’t go thinking that this is a falsely positive impression brought on by the deeply ingrained perception of Land Rovers needing to have dirty great diesels in order to function. There’s no doubting the Si4’s luxurious smoothness, its diesel-shaming performance, or the ease with which it removes the more powerful supercharged six-cylinder petrol option from the buying equation.
If you’ve been longing for a versatile seven-seat luxury SUV that runs on petrol, the Discovery Si4 should feature on the shortest version of your short list. Having said that, unless you absolutely cannot see your way clear to owning a diesel, you’d still be well advised to check out the range-topping TDV6. The petrol unit is quicker and more refined, but it’s not as economical or CO2-clean, and nor is it as flexible as the diesel. Plus, the TDV6 premium is only £650 if you go for SE trim. You’ll pay more than that just to tick the ‘keyless entry’ box.