Let’s face it, if you’re considering the most powerful five-door compact hatchback on the market and expecting it to be inexpensive to run, you’re in for a shock. Chances are, despite some weight saving measures and standard stop-start function, Audi RS3 Sportback running costs are going to be high.

The firm claims the latest RS3’s 2.5-litre turbo engine will average 34.9mpg, although in the real world a figure on the wrong side of 28mpg is more likely, especially if you drive with it with vigour.

Consider BMW’s M135i (37.7mpg) and Mercedes’ A45 AMG (40.9mpg) offering superior fuel efficiency without sacrificing too much performance, the Audi has got its work cut out to compete.

A greater thirst for super unleaded petrol equates to higher CO2 emissions too, impacting upon VED car tax bandings.

Plus there’s the cost of the insurance premiums, expensive tyres and, if you’re very unlucky, replacement ceramic brakes to factor in. And that’s before you get the car serviced bang on time to preserve its resale value. It all adds up.

With just one engine and gearbox combination, Audi RS3 Sportback emissions are pegged at 189g/km of CO2.

Compared to its key rivals – BMW M135i, 175g/km; Mercedes A45 AMG, 161g/km – it’s a high figure, even though Audi’s fitted the RS3 with standard stop/start and it’s shed some weight versus the previous generation car.

That said, the hallowed five-cylinder engine is fully-compliant with EU6 emissions regulations.

Given how problem-free the regular A3 and sportier S3 models are, the likelihood is that Audi RS3 reliability should be impressive too.

There’s a caveat there though: although it’s self-evidently a compact family hatchback, underneath that predominately unassuming exterior is a high performance sports car and consequently it needs to be cared for. Ensuring it’s serviced on time and maintaining it in excellent order will maximise its chances of a trouble-free life.

Elsewhere, the standard A3 parts, such as the switchgear and other interior components stand the test of time very well, so there’s no reason the flagship of the range will be any different. Build quality is first rate and the materials used are of the highest order – other manufacturers, premium and otherwise, have lots still to learn about car interior construction.