From Luton to Hethel in the 180mph Lotus Carlton

But Vauxhall wanted to let the car do what it could do. “I did a thing with [then land speed record holder] Richard Noble at Elvington airfield,” Tearle says, “setting top speeds in this and a Monaro. I remember hitting the brake board in the Carlton with the speedo pointing to six o’clock, which we worked out to be 186mph.”

There were similarly fast cars at the time: Lamborghinis and Ferraris and other exotics, but none had the audacity to wear a Vauxhall badge on their nose, an apparent problem even though that was entirely the point of the exercise.

Besides: 155, 176, what difference would it have made? Russell Bulgin, writing for Car magazine and later an Autocar contributor, took a Carlton to Germany to annoy “those po-faced word-sharks who berate Vauxhall for producing a 176mph saloon car and then stand first in line for a road test where they will, natch, be taking performance figures”.

Fair dos. We did. The Carlton did 0-60mph in 5.1sec, 0-100mph in 11.1sec and 30-70mph in 3.8sec. The base Carlton was built by Opel in Rüsselsheim, Germany, then came to Lotus for the modifications that made such outrageous performance possible.

“Cars would arrive on a transporter as a 3.0 GSi,” says Tearle. “They’d take it to the workshop, put it on a ramp, drop out the suspension, engine, transmission, take all the glass out, all the interior trim out. “It was a very costly and time-consuming process, because they then cut the wheel arches, cut a new place for the gearlever, had to do all the bodywork – bumpers, spoilers, rocker panels. The interior trim was totally re-covered. There was a different rear axle, ZF gearbox (most GSis were automatics), while the engines were totally stripped and went for a rebuild.”

After some porting, the addition of two Garrett turbos and the straight-six engine’s capacity had been increased to 3.6 litres, the Lotus-tuned and hand-assembled unit made 377bhp.

Later still, Autocar also took one to Germany to try to reach its top speed. Then, as now, derestricted autobahns were where cars like this, which add speed quickly even when deep into three figures, make most sense. I recently hit 180mph on an autobahn in a Mercedes-AMG E63 with no drama, no fuss – and no questions-in-the-house controversy.

Today, though, the Carlton will be going from Luton to Hethel, Lotus’s home – a journey Tearle made a couple of times a week when the 949 Lotus Carltons were in production. (Tearle says the 950th and last was damaged on the production line at Rüsselsheim and never built.)

At the time, the Carlton was a big saloon but, inevitably, given its thin roof pillars and that it’s only around 1.8m wide across the body, it doesn’t feel it today. The steering is heavy and slow and so is the clutch, while the driving position, owing to a rake-only adjustable steering wheel, is long-armed. But you can feel it’s a car built for long journeys at big speeds. The gearbox is long and slow (this six-speed manual, used first in the Corvette but also in Aston Martins and other low-volume cars, always was) and geared for the heavens. Top speed arrived in fifth gear, and in sixth, at 1000rpm, I’m doing 46mph.

Some of this car feels old. There’s a little driveline shunt (it’ll probably want a new differential at some point) and, as cars get older and spot welds creak, classic cars do risk feeling similar: as you steer, you take up the slack in the body and in bushes and joints before you get much response. Like watching an ageing sportsperson, you can see the gifts are still there but everything is a little dulled and slowed. But the engine is still magic.

There’s barely any turbo lag as it gets going early and keeps pulling with the kind of smoothness that only multiples of straight six offer. It still feels fast today and, even though it was outrageously so 30 years ago, sometimes that wasn’t enough.

“A lot of people did modify them,” Tearle says, “pushing the performance from 377bhp to 500bhp, 600bhp. When we had cars back [for service or warranty work], we’d get the dealers to remove the glovebox. There was a Lotus sticker over the ECU which would burn ‘void’ into it if removed. A lot of cars were modified but you could always tell: they were very tired and the engines were noisy. When you drove a car that had been [left] standard, you knew without looking at anything else because it just felt right.”

The engine in this car still does. If you were to restomod a Carlton, you’d stiffen the shell, quicken the steering and maybe mount the driving seat lower, but you could leave the engine well alone.