If I have learned anything in this business — it’s that one shouldn’t prejudge.

I approached the new Mercedes-Benz SL 63 AMG expecting it to be big, fast and heavy.

Because that’s what the last few cars to bear the SL badge have been.

Somewhat ironic, in that “SL” originally stood for “Schnell” — fast — and “Leicht” — light.

The new car goes on sale in Canada in July. Our price hasn’t been determined, or at least not announced, but in other markets it is actually a shade less than before. Our current SL AMG is $166,000, so expect somewhere around $160,000.

The new generation SL AMG is all of fast. With 537 horsepower in base trim (564 with the optional “performance package”) it may not have “the world’s most powerful production V8” as AMG board member and director of vehicle development Tobias Moers suggested (he backed off to “one of the world’s most powerful production V8s” after I reminded him of the Corvette ZR-1).

But the 5.4 litre twin-turbo does shove the car from rest to 100 km/h in a click or two over four seconds and to an electronically-limited top speed of 250 km/h, if your driveway is long enough.

More important in the real world, the 590 lb.-ft. of torque (663 with the performance package) on tap from 2,000 to 4,500 r.p.m. means a two-lane pass is a mere flick of the right ankle.

AMG is also quite proud that the engine earns a combined European fuel consumption number of 9.9 litres per 100 km, pretty impressive for a car this powerful.

Bolted onto this engine is the AMG seven-speed automatic transmission with electro-hydraulic multi-plate clutch in place of a conventional torque converter.

This provides lightning-quick shifts, either automatically or driver-induced via the shift lever or steering wheel paddles.

It also does rev-matching when downshifting, to make everyone feel like they’re Sebastian Vettel.

Four modes are offered:

C (for “Controlled efficiency”) provides earlier and softer gear changes, and now includes an idle-stop function which shuts the engine off to save fuel when the vehicle is stopped.

S (“Sport”) and S+ (just guess) offer increasingly quick response from all powertrain systems, while M (“Manual”) leaves it all up to you.

I found C just a shade too “Controlled.” I wondered if maybe the traction control system was activating, because it made the car feel quite sluggish.

M is perhaps more involving than you’d want in normal driving; S+ was perhaps my favourite.

The thing is — you do get a choice, depending on your mood, and circumstances.

For example, when returning through the incredible traffic in Saint-Tropez — and it wasn’t even holiday season yet — after the fun and games in the hills, C wasn’t so bad after all.

Getting back to big: a two-seat sports car — big? Everything looks bigger on the narrow roads of Europe than it does back home.

There were occasions in town and even on some of the rural roads where the oncoming dump trucks looked awfully threatening.

But if they can pass each other, this car must be able to fit too.

The surprise came when we finally figured out how to extract ourselves from downtown Saint-Tropez and work our way into the hills.

Hey — this thing turns in!

At 1845 kg (4,067 lb.) the new SL 63 AMG won’t be competing in the Olympic featherweight boxing class. But the all-aluminum body structure and details like a carbon fibre liner for the trunk lid make the car some 125 kg lighter than its predecessor.

Am I trying to tell you I am sensitive enough to feel a seven per cent decrease in weight? No.

The car actually felt a lot lighter than that and much credit is due to the revised suspension on the AMG variant.

The car retains the ABC — active body control — system, whereby hydraulic activators monitor suspension and body movement and influence the steel coil springs to allow just about any degree of body lean the engineers want.

Moers mentioned that they don’t want zero body lean — that would feel unnatural — but the car certainly stays very flat in the corners.

What’s more important is how the car arrives at that particular degree of list — it should be smooth and progressive, so as not to disturb the suspension, hence affect the tires’ contact patches with the pavement.

Moers also described the changes in the AMG variant relative to the new regular SL, which include a new upper-front suspension arm, different bushings for revised elasto-kinematics (how the suspension deflects under load) and significantly increased camber — from 0.8 to 1.8 degrees at the rear, for example — which gives the car much better agility.

You also get two settings for the suspension to stiffen the car as required or desired, and three settings for the electronic stability control system too.

It felt as if there were no limits to the grip at all.

Consistent with AMG philosophy, the electro-hydraulic steering has a constant ratio — ease of parking not being considered as important on a sports car as consistent steering response.

Steering effort is light — perhaps too light in C mode.

Again, Moers mentioned that this can be adjusted via software upgrades.

“We may not have finished with the steering,” he said.

A new optional composite braking system ensures that if you get in too far over your head, the brakes will do their utmost to bail you out.

You’d need way more than a couple hundred klicks over a short day to evaluate all the combinations and permutations offered by this car, but I could make the time.

Suffice it to say that it can be a fierce sports car, or a comfortable luxury Grand Tourer, at the flick of, well, several switches.

All this is wrapped in bodywork that is essentially the same as the new regular SL, with some AMG touches. The crosspiece in the grille is double-bladed, the front air dam and LED daytime running lights are AMG-exclusive, and the quad chrome tailpipes incorporate the AMG logo.

The interior is still fairly cramped, given the car’s overall size, but it is beautifully finished and equipped with all the modern conveniences luxury car buyers have come to expect.

AMG is an interesting outfit. A wholly-owned subsidiary of Mercedes-Benz, it maintains a remarkable degree of independence, providing what AMG’s head of branding and marketing Mario Spitzner refers to as “The Mother Ship” not only with upgraded engines, suspensions and design packages, but in the case of the SLS Gullwing coupe and Roadster, complete cars.

Not to mention in the case of the SLS, Mercedes’ first foray into production aluminum body work, which has been carried over into the regular SL.

When you buy an AMG product, you also buy into this heritage.

And when you buy an SL 63 AMG, you’re also buying a hell of a sports car.