As a rule, car company people from one marque don’t talk about rival brands - partly because they don’t want to shine the light anywhere but on themselves, and partly because any comparisons can be a bit unseemly.

But it’s very hard for a premium brand to talk about launching an electric car these days without it being described as a Tesla beater. So much so, that one senior engineer told me recently that there isn’t a premium or aspiring premium car maker that doesn’t have a document headed ‘Project Tesla Beater’ active right now.

So when Audi technical boss Ulrich Hackenberg confirmed yesterday that the Audi E-tron Quattro concept will spawn an all-electric SUV in 2018, the inevitable question came in as to what would differentiate it from what Tesla has been doing already for several years.

Hackenberg is one of the very finest people we work with; fiercely clever but open, and happy to passionately discuss any topic. That said, if I’m honest, I’m not entirely sure his answer hit the spot in terms of explaining the five-plus year time lag from Tesla to Audi in launching such an all-electric car.

“For us the big jump is that we are offering such a car,” he said. “Our organisation and our relationship with our customers is totally different to that of Tesla.

“Customers going to a brand new brand are very free-thinking and have a part of their character that likes to try something new. If it’s not very good, okay, in a month or two they will try something else. Most of them have several different cars, and if one of them is standing with a problem, they’ll just take another one.

“But with Audi it’s different. An Audi has to run and if an Audi has a problem, it’s a huge problem to the customer. So we have to take more care about reliability. That means we have taken more time. As Audi, we are not allowed to have problems.”

The irony, of course, is that the established car makers now face a huge battle to disrupt the position established by the arch-disruptor itself, Tesla. I’ve few doubts development budgets and brand power will eventually win through, but I’m equally sure we’ll end up looking back on Tesla’s arrival in the automotive world as far more pivotal than its sales volumes may suggest today.

In response, a Tesla spokesman told me: “Part of the reason that Tesla was founded was to make a change and push forward the development of sustainable transportation in an industry that had considered electric vehicles, but deemed them too expensive to develop or too much of a move from their traditional models.

“We are delighted that the big manufacturers have started to move forward, the only shame is that they are still talking about cars that are three to five years away and aren't available for consumers to buy today like Model S.

“In terms of customer satisfaction and repeat purchases, our consumer reports survey results - which are the highest of any manufacturer - are testimony to the satisfaction of our customers. Most will say they will never go back to driving anything other than zero emissions and many have purchased a second Model S to complete their move away from fossil fuels.”