Our Jaguar F-Pace SVR is lying about its fuel economy...
Confession: I keep spreadsheets of fuel economy. Everyone’s got their geek side, right? Well that’s mine. Every time I fill up I note the miles, the litres, the cost and the trip readings. The spreadsheet coughs and splutters and creates yet more figures: actual mpg, fuel cost per litre, trip mpg deviation. See, proper testing.
Anyway, I’ve been doing it especially assiduously since fuel prices have gone ballistic. Because the costs are terrifying, aren’t they? Obviously running a supercharged V8 is still far cheaper than public transport, but this one has an 82-litre tank, which means I’m staring down the barrel of a £150 refuel every 350-380 miles. I’m not feeding this thing super. I’m just not. It doesn’t insist on it, so that’s not far off a tenner saved each time.
But there’s not much we can do about fuel costs at present: there’s a war on, and the energy companies seem to be displaying ruthless greed. Record profits and so on. We can govern our costs a little by driving more efficiently. Jaguar claims a combined 23.1mpg for the F-Pace SVR, and I’m often bettering that. The trip computer tells me I’ve averaged 25.5mpg over the 1302 miles I’ve done this month.
But the trouble is, I haven’t. Using 257.80 litres I’ve actually averaged 23.0mpg. Pretty much exactly what Jaguar says the car should be doing. But not what the car tells me. In fact there’s a discrepancy of over 10 per cent between what the car’s trip computer says it’s doing, and what it’s actually doing. And I’m afraid to tell you that if you drive a Jaguar Land Rover product, it’s highly likely your fuel economy is 10 per cent out as well. Over the years I’ve run a Velar D300, Discovery 5 and Jaguar F-Type R and every one of them had similarly inaccurate fuel readings.
I’ve cross checked this with other cars – the Porsche 911 I ran last was around 1.5 per cent out, both the Mercedes A45 AMG and Audi RS6 were 4-5 per cent out. But JLR products appear to tell the biggest porkies. Jag’s official line is that the difference shouldn’t be more than five per cent, but without running diagnostics they can’t be sure why this one is inaccurate. I pointed out it’s been the same with all JLR product and was told, “accuracy can be influenced by factors such as driving style, fuel type, ethanol content and car-to-car variability".
This matters to me, because if the trip computer was accurate I would actually think that 23.0mpg was a fair result for a 550bhp supercharged 5.0-litre V8 punting two tonnes of bluff SUV down the road with maximum prejudice. But the knowledge that the trip computer is trying to hoodwink me at every turn is annoying. And unnecessary.
To be fair, it’s a price I’m willing to pay for the noise alone, let alone the uncanny thrust this thing develops. The sound is utterly glorious. I thought the EU had clamped down on excessive exhaust flatulence, but this is a proper old school V8, the kind that tickles your ears in just the right way, even without the loud button pressed. It’s absolutely addictive and not just at high revs. The rumble and thunder is there on light throttle openings, felt and heard through the cabin. It’s another side of my inner geek.