Twin test: BMW M5 '30 Jahre' vs Lexus GS F

A simple straightforward head to head between the new Lexus GS F and a BMW M5. And yes, it's a '30 Jahre' edition M5, not because it swings the power barometer even further in the M5’s favour, but because it was the only one that BMW had.

In case you’re unfamiliar with the 30 Jahre, here’s what you need to know: it came out the year before last to celebrate 30 years of the M5, only 300 will be built and power from the twin turbo 4.4-litre V8 has risen from 552bhp to 592bhp, its 0-62mph acceleration time dipping to under four seconds for the first time ever.

The suspension is dropped 10mm, the springs and dampers are tighter, the Active M Differential and stability control have been tweaked, and the steering is more direct. It is, on paper at least, a bit much for the Lexus to contain.

Photography: Simon Thompson

It’s a bit of a curiosity, the GS F, because it uses a naturally aspirated engine. It may be a 5.0-litre V8, but it doesn’t have the M5’s torque, uses a traditional eight-speed auto instead of a seven-speed double-clutch, and falls short in the numbers department. 

Try these on: the GS F's 471bhp and 390lb ft at 4800rpm play the M5's 592bhp and 516lb ft, and the BMW delivers its clout anywhere between 1,500rpm and 6,000rpm. To say the M5 is well endowed with torque is to sell it very short. It’ll also hit a 199mph top speed to the Lexus's 155mph.

And I’m afraid it continues. Where a standard M5 costs £73,970, broadly in line with the £69,995 GS F, this one is £91,890.

But let’s draw a line under all this and consider the simple question of whether Lexus makes a car that’s as well honed, capable and amusing as the M5. Because the answer is a little surprising.

That depends on your perspective. Personally I was quite a lot surprised. Having driven and been underwhelmed by the RC F coupe (lovely engine note and response, but way too heavy, so it barges about a bit clumsily), I was expecting more of the same.

Instead, the GS F is a bit of a sleeper. It only weighs a little more than the M4-rivalling RC F (and is 80kg lighter than the M5), but the weight seems to be more neutrally balanced between front and rear axles, so it moves pleasingly and is reasonably adjustable on the throttle.

That throttle is also very sensitive, crisp and responsive to inputs and the fixed-rate dampers (no adaptive jobs here) have been thoughtfully set-up, so it does the cruising and kick-arse stuff with aplomb. It shows that endless modes aren’t necessarily the way to go.

I didn’t say that – only that the dampers are fixed. If only Lexus had taken that on board in other areas, because there are then selectable settings for the diff, stability and engine/gearbox, none of which quite hit the mark. Sport S, manual gears and some form of sportier diff setting seems to be the way to go. Well, as long as you’re above 3,800rpm.

Because that’s the point where the engine’s valve timing wakes up, exhaust baffles open and the good stuff spews forth. It marks the point where the GS F ceases to be an exec barge and becomes a guttural, roaring super-saloon. There’s a real duality to the Lexus’ character, centred around that step-change point in the revs, that is invigorating and exciting.

It does, but it’s less marked, partially because the turbos rob the engine of a little noise and character (but by no means all of it), but also because it’s governed by what modes you’ve selected for the suspension, steering and so on. Even then, if you don’t properly drive the 30 Jahre, you’d be forgiven for thinking it not much more than a supremely effective dispatcher of autobahns.

It’s a big car, more cosseting and distant than the GS F, but when you go looking for adventure in it, boy does it gee itself up. The steering is a delight, so much better than the Lexus’ more digital, feedback-free set-up, and the suspension suddenly seems to key itself into the road.

Yes, it feels wider than the Lexus on a B-road, but it’s easier to pick an accurate line and hold it in the BMW.

It’s certainly more comfortable in mooch-mode. Although a good chunk of this is down to the fact it has a vastly superior cabin – better seats, far more logical infotainment, slicker design, it’s also the more refined and soothing.

Is it the sportier of the two, though? Arguably not – the Lexus actually comes across as the more visceral and aggressive, and is that bit spikier and more challenging if pushed.

The M5 takes longer to reveal its true colours, but when you dig down into it, the thing’s an absolute weapon. The GS F is not slow – third gear feels rampant – but the M5 is on another level. Of course, you can’t deploy anywhere near as much firepower for anything like as long as you’d want, but the exponential, expansive thrust the M5 generates is genuinely shocking.

And how something that weighs over two tons once you have a driver on board can maintain its composure and finesse on a difficult road is actually quite bewildering.

For the Lexus, the gearbox and economy. A high-revving naturally aspirated engine fitted in a chunky executive saloon isn’t a recipe for efficiency – or particularly in keeping with Lexus’ hybrid reputation. They say 25.2mpg, we say 21-22. The BMW, even with an extra 121bhp, is an mpg or two better.

Then there’s the auto gearbox. The upshifts aren’t bad, and at low speed it drives off the line more cleanly than the BMW’s twin-clutch (nice around town), but the downshifts just won’t keep up with your demands. It becomes frustrating all too quickly.

For the BMW, the drawback is the price. We wouldn’t blame you for saving the best part of £20k and sticking with the standard M5, although it has to be said, this 30 Jahre is markedly better – more decisive, feelsome and immediate. The only other thing against the BMW is its size – it’s a big, wide car and feels it.

It is. But what I’m trying to convey is that you shouldn’t write the Lexus off – in fact although this isn’t a very super-saloony comment, if the Lexus had a simpler, more satisfying interior design and a less hopeless infotainment system (the mouse set-up is utterly awful) it would have run the BMW closer.

The GS F is a less polished, honed and deft product than the M5, the Hyde side lurking closer to the surface. But there’s something to be said for that: it’s a little less grown up, arguably the more fun, thrashable and amusing of the pair.

Still, given a straight choice, I’d take the M5. It is irritatingly good.