Skip advert
Advertisement

BMW 6 Series vs M635 CSi

BMW says its new 640d will be the best-selling 6 Series ever. How does it match up against legendary eighties M635 CSi?

BMW 6 Series vs M635 CSi

Believe it or not, the new diesel version of the BMW 6 Series is predicted to account for an incredible 93 per cent of the model’s UK sales. The company expects the 640d to be the most successful version yet, and it’s easy to see why.

Here’s a car that can sprint from 0-60mph in only 5.4 seconds, yet return claimed economy of up to 51.4mpg. Low emissions and a four-seater interior packed with gadgets do the rest.

Advertisement - Article continues below

The newcomer is in a class of one, because none of its rivals offers the option of a diesel engine. As a result, nothing on sale today comes close to matching its mixture of talents, so we decided to look to the past instead.

In 1986, the BMW M635 CSi set the benchmark for luxury GT performance cars. It was fitted with the same 3.5-litre engine as the legendary M1 supercar and its combination of blistering pace, rear-wheel-drive handling, muscular styling and cosseting comfort gave it cult appeal. And after 25 years, it has become a bona-fide classic.

The new diesel 6 Series may be faster and more economical than its potent petrol ancestor, but can it really live up to the legend?

Verdict

An impressive debut – the 640d’s new diesel engine, long-haul comfort and luxurious cabin all make an impression. Not only is it faster, cheaper to run and nearly twice as economical as the M635 CSi, it also has a dazzling array of technology and safety equipment. It’s no lightweight, yet with the optional Adaptive Drive dynamics, it’s a remarkable machine.

But so is the M635 CSi. No matter how good the 640d’s engine is, it can’t match the spine-tingling soundtrack and pin-sharp responses of the old timer’s straight-six powerplant. Sure, its handling isn’t up to modern standards, but the M635 CSi is utterly engaging to drive.

Which is better? As they’re from different eras, direct comparisons are pointless, but what the 640d does demonstrate is how much progress has been made in the last 25 years. We’d love to have both cars on our driveway.

1. BMW 640d

The 6 Series Coupe is better than ever, especially in diesel form. Its effortless ability to cover big mileages is peerless in this sector of the market, and the phenomenal performance of its twin-turbo engine means that even petrol-loving diehards won’t be left feeling short-changed.

2. BMW M635 CSi

There's no denying the sense of occasion and nostalgia that comes attached to a car like the M635 CSi, even if you weren’t around to see it first time. Driving one is an intoxicating experience and as one of the first BMWs to wear the M badge, it deserves a special place in automotive history.

Skip advert
Advertisement

New & used car deals

Skoda Kodiaq

Skoda Kodiaq

RRP £38,140Avg. savings £3,450 off RRP*Used from £11,895
MG MG4

MG MG4

RRP £26,995Avg. savings £6,040 off RRP*Used from £12,300
Volkswagen Tiguan

Volkswagen Tiguan

RRP £35,385Avg. savings £2,919 off RRP*Used from £14,800
Nissan Qashqai

Nissan Qashqai

RRP £27,415Avg. savings £5,924 off RRP*Used from £12,695
* Average savings are calculated daily based on the best dealer prices on Auto Express vs manufacturer RRP
Skip advert
Advertisement

Most Popular

Citroen recall sees owners told to stop driving “immediately”
Citroen C3 Mk2 - front tracking

Citroen recall sees owners told to stop driving “immediately”

A ‘Stop-drive’ order has been issued by Citroen following a fatality that may have been caused by a faulty Takata airbag
News
20 Jun 2025
Car Deal of the Day: a potent 335bhp Volkswagen ID.7 GTX for a rock bottom price
Volkswagen ID.7 GTX - front static

Car Deal of the Day: a potent 335bhp Volkswagen ID.7 GTX for a rock bottom price

GTX Plus gives some extra punch to an already excellent electric saloon. It’s our Deal of the Day for 20 June.
News
20 Jun 2025
New Skoda L&K 130 shows us what a Superb pick-up truck looks like
Skoda L&K 130 - front static

New Skoda L&K 130 shows us what a Superb pick-up truck looks like

Skoda’s 10th ‘Student Car’ is a plug-in hybrid that would be an ideal support vehicle for the Tour de France
News
20 Jun 2025