Currently reading: The 100mpg challenge: Pushing my 22-year-old Audi A2 to the limit

Can an old diesel Audi achieve a three figure mileage score? There's only one way to find out

Given that my Audi A2 was returning 75mpg in normal use, I had idly wondered what I could get out of this 1.4-litre diesel hatch if I tried.

It was a bank holiday Monday, I was in no rush and I was driving from Bicester to Petersfield and back to visit family. So I had a go. Traffic was light, I found the odd van to slipstream and nobody had binned a BMW M3 into a hedge on the A272. The answer, without trying that hard, because I don't like being a 40mph menace, was 94mpg.

I figured I could do better than that. In fact, I thought I could get 100mpg out of it. Which is why I'm on the A34, again, with nearly a full tank of fuel, again, and slipstreaming a truck, again – not so close as to be a nuisance but not so far back that there's no benefit. This time, though, I have a goal, and a Morgan Plus Four with a cameraman hanging out of it for company.

I'm driving from a filling station near my house to the seafront in Lee-on-the-Solent. Snapper Jack Harrison wonders if it's because that's where the hovercraft museum is and hopes we will have time for a visit.

Alas, no (and it's shut on weekdays): it's just precisely 100 miles from where I started, according to a map. I've calibrated the odometer (against motorway kilometre markers) and the trip computer (via brim-to-brim fills) so I know what level of fibs they're telling.

Not very big ones, as it goes, and they're pessimistic ones. If the trip says I've done 100mpg, I'll have done closer to 103mpg. If the trip says it's right, it's right: I'll have used less than a gallon of fuel to cover 100 miles in a 22-year-old hatchback.

I love this old hatchback. To recap, early last year I paid only £500 for it, because it didn't have an MOT. I thought I'd keep it for 1000 miles and then sell so I could write about how you can be paid to drive, but it has become a car I use all the time and can't imagine selling.

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I was going to check the wheel alignment before today. But with the kind of disorganisation that comes with being an idiot and working on a weekly car magazine, all I've done is remove the back seats, pump up the tyres to 40psi and give it a clean.

I have a few concerns about my mission. One is HS2-induced roadworks near the start of the journey, the other a congested ring road. But here I shouldn't have worried, because it turns out that 40mph-ish touring on a little more than idle is actually about perfect. By the time I reach the A34, only a few miles into the journey, the average is around 104mpg.

It turns out that the A2 prefers motorways or dual carriageways less. When one Luton box van I'm behind departs at a junction near Oxford, I'm sitting at 55, 54, 53, 52mph... watching my average mpg drop from the high-90s to the mid-90s. And I'm waiting, hoping, desperate for another to arrive from an adjoining slip road.

What to do? Drop back and become a mobile road block until I can latch onto a passing truck? Or put my toe in to catch a lorry half a mile in the distance? In the end, a couple of times, I sort of do neither, flounder, and by the time the A34 meets the M3, I'm not at all sure I'll manage it. The economy readout sits deliciously in the balance: high-90s. If I get a break, the A2 might just do what I need.

My break comes in the form of 40/50mph speed limits on the M27 through roadworks. The A2 is in its element and my consumption meter is heading closer and closer to 100mpg. Joining the slower roads to the coast seals it: the odometer thinks my journey isn't quite 100 miles, so after a brief tour of Lee-on-the-Solent I pull into a seafront car park, shamelessly park nose first and switch off the engine.

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The car says I've done it: 100.9mpg. I'm very pleased. Beyond very pleased. Yes, I know if it were electric I'd have burnt no fuel whatsoever and we do live in an age when there should be abundant clean energy. But that wasn't the point of this exercise.

This car might have expired after a couple of months and I couldn't have complained about it. But several thousand miles after buying it, I've totted up the sums and, if I sold it for what I think is its market value, it would still have cost me approximately zero pence per mile to run. But I think it's time I spent a few quid getting it looked after. It deserves it.

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Matt Prior

Matt Prior
Title: Editor-at-large

Matt is Autocar’s lead features writer and presenter, is the main face of Autocar’s YouTube channel, presents the My Week In Cars podcast and has written his weekly column, Tester’s Notes, since 2013.

Matt is an automotive engineer who has been writing and talking about cars since 1997. He joined Autocar in 2005 as deputy road test editor, prior to which he was road test editor and world rally editor for Channel 4’s automotive website, 4Car. 

Into all things engineering and automotive from any era, Matt is as comfortable regularly contributing to sibling titles Move Electric and Classic & Sports Car as he is writing for Autocar. He has a racing licence, and some malfunctioning classic cars and motorbikes. 

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si73 10 February 2026
Awesome results, shows how good the car was in the first place, I’d happily sacrifice the economy for the smoother quieter petrol engine personally, plus I don’t do the distances to justify a diesel but I’ve always liked the A2 and the similarly sized original A class.
Bob Cat Brian 9 February 2026

Great piece, if a little brief, is this an abridged version of a longer piece in the actual magazine?

I absolutely loved my A2, which I bought for a similar amount to tide me over for a few months about 8 years ago. Only my current i3, which could be seen as a successor from another brand, is higher in my affections of all the cars I've owned. 

audiolab 9 February 2026

What would this car would achieve with a more modern engine/gearbox installation.

My now departed Seat Ibiza 1.6tdi, i regularily managed 60mpg without much effort on some longer runs hit over 70mpg. I wonder what i could achieve in a modern diesel. I now drive petrol and only dream of these fuel economies.

dandmonty25 15 February 2026
2014 Leon owner here, with the same engine in 105hp tune.

I've seen 83 mpg on a 20 or so mile journey from hell stuck in the 40-50 mph club, due to a combo of dawdlers, light congestion, and a stretch of dual carriageway vandalised by average speed cameras.

Driven properly it gets 50-odd mpg consistently.

I'm not gonna say everyone should hoof it wherever possible, but deliberately sitting behind large slow moving vehicles is perhaps not best practice either.