Bentley Flying Spur vs BMW M5

What's the difference?

The Bentley Flying Spur Speed is a whole lot of car, for a whole lot of money. Sure, I’d rather have a Ferrari or a Porsche with similar power (and the Panamera shares the same V8 and hybrid set up), but then if you’re in the market for a Bentley like this you already have a garage full of other options. And I can see why you’d add one of these to your collection. Because you can.

Note: CarsGuide attended this event as a guest of the manufacturer, with travel, accommodation and meals provided.

Let’s get one thing out of the way: the new M5 is a very good car. Considering the emissions limitations and size increase of its base model, it is an impressive bit of engineering. 

What’s trickier is deciding whether the new car is really better to drive. Less edgy but supremely comfortable and quiet; BMW leaned into the daily usability of the plug-in hybrid M5 rather than amping the petrol-electric system for maximum thrills. And do you know what? That’s fine with me. 

The new M5 still performs on road and track and does an incredible job of hiding its weight (most of the time). Perhaps the G90 is a little more Audi RS6 than F90 in its demeanour but some would argue that’s no bad thing. 

The concept of the BMW M5 is not static, it evolves with the times, and the G90 is no exception. Expect future Competition and CS variants to unlock some extra lunacy. 

Note: CarsGuide attended this event as a guest of the manufacturer, with meals provided.

Bentley seems to have spent the design budget on the Continental GT Speed, which was launched at the same time and gets the same new engine under its slightly sexier bonnet. The big move there has been going from Bentley’s traditional four headlight face to a smoother more modern one with just two lights, or eyes.

The Flying Spur, by comparison, sticks with the more traditional look, and four eyes, but that doesn’t necessarily mean it looks nerdier. Indeed, it’s still an impressive and handsome beast and does a mighty fine job of making this much metal and mass look bold and desirable. 

Truly, vehicles this large tend to look lumpen and making one look as good this Flying Spur Speed does is an impressive feat. Look at the photos and be impressed.

The interior fit out and fittings are stunning, with Bentley boldly claiming it makes the best car cabins in the world. It’s not an outrageous claim, either.

The M5’s raw size is what you notice first. The G90 M5 is a whopping 113mm longer, 67mm wider and 37mm taller than the car it replaces, with the wheelbase stretched 24mm.

It is also the most pumped M5 yet, compared to a 520i it is 70mm chubbier at its flared wheel arches. The ‘M5’ insignia on the C-pillar means you’ll know this is the fast one. 

Presence is not in question, then, but beauty? Not the right word. The G90 makes its predecessors — especially the original ‘E28’ — look demure. 

The cabin layout builds on the concept debuted by the iX electric SUV, with twin integrated screens and focus on technology and minimal buttons. Materials are mostly high quality and feel fitting for the M5’s asking price.

I’m not going to pretend that I had my laptop out taking notes while we were hitting 200km/h down the back straight at Magarigawa, but at more sane speeds there’s no doubt the rear seats of this car would be a very relaxing, plush, cosseting and pleasant smelling place to sit and work.

That’s at least partly what the Flying Spur Speed is for, a limousine for those who don’t like, or perhaps can’t quite afford, a Rolls-Royce, but still want great British solidity, class and that sense of obscene wealth, probably inherited.

The bonus of the Flying Spur is that it’s also a lovely place to be should you choose either of the front seats, with hugely comfortable seats that are more like couches, endless adjustability and many soothing massage settings for your heated and ventilated pews.

The spinning central 12.3-inch display remains the highlight, offering you a modern touch screen, which can disappear to reveal either three classic analogue dials or a plan piece of dashboard, if you prefer a “digital detox”.

BMW has persevered with its twin-screen, minimal-button approach for its 'Operating System 8.5' in the M5. 

The 14.9-inch central touchscreen is bright, responsive and high resolution but the software remains a little strange. The main interface is classy but when looking for settings to adjust you’re presented with a Windows 95-esque panel of small square touch targets. It’s not intuitive. 

Wirelessly mirroring Apple CarPlay or Android Auto works a treat, at least. Digital climate controls keep temp adjustment persistently on screen and a shortcut to fan speed. The nipple-like vent direction adjustment grows on you, as do the digital vent sliders. 

The 12.3-inch digital driver’s display still doesn’t have the freedom of customisation and clarity of Audi’s interface. 

The M5 has two cupholders, a deep central storage cubby, door bins that swallow two 600mL plastic bottles and twin wireless charging pad that resolutely grips smartphones even under the sort of tummy-churning G-Forces this M5 can manage. 

Setting the M5 apart from the regular sedan is a unique centre console bunching 'M Drive' modes, 'M Hybrid' modes and other shortcut functions together next to the gear toggle and M-engraved crystal 'iDrive' controller.

Comfortable front seats are power adjustable with in/out, up/down lumbar support and have two memory positions. 

The 5096mm long M5’s back seat is very spacious. Headroom is good for those beyond 182cm (six-foot), the bench is extremely supportive, while leg and toe room are adequate.

A fold-down centre armrest has two cupholders and there are USB-C charge ports in the back of each bucket seat for a total of four. 

You can buy an accessory mount that holds tablets or smartphones for rear seat passenger entertainment, too.

When you look in the boot, BMW offering a Touring version of the latest M5 makes even more sense. The load aperture is big but the usable space is narrow; the sides intrude on load space. 

The 466-litre space will make fitting suitcases for an airport run tricky and, even with the 40/60 split-fold rear bench, you will struggle to fit a bike in the back. There’s no spare tyre, either.

The last M5 was well equipped but the new car is wanting for nothing. Australian cars have just about every option for $259,900, before on-road costs.

Australian M5s wear staggered 20-inch front and 21-inch rear alloy wheels paired with standard metallic paint, 'M Carbon Exterior' package (including carbon roof and rear lip spoiler), adaptive LED headlights and BMW’s 'Iconic Glow' illuminated kidney grille surrounds. 

Keyless entry, a heated steering wheel, heated and ventilated front seats, interior camera, powerful 18-speaker Bowers & Wilkins sound system, M seatbelts, four-zone climate control and a power tailgate are the cabin highlights. 

Optional extras are thin on the ground; you can choose from (eight) no-cost paint colours and all manner of 'Individual' shades (from $4100), four interior trims including classy 'Dark Oak' wood and four leather colours. There’s classic black ‘Merino’ leather, or you can have it dyed with a mix of 'Silverstone', red or 'Kyalami Orange'. 

Aside from that, the only major option is carbon ceramic brakes at a staggering $18,500, and an M5 Touring wagon costs $263,900. 

Though the M5 is more expensive than Audi’s closest rival, the RS6, the gulf isn’t huge considering you get a lot more punch in the BMW. Mercedes-AMG does not have an E-Class answer, yet.

Good value, then? Well, an equally potent Porsche Panamera is twice the price. So yes, in a sense.

If you’re going to put the word “Speed” in the title of your car, you really can’t mess about when it comes to the powerplant, and Bentley also has a proud history of making hugely powerful V12 engines to live up to. That’s a history that has now ended, with the announcement that the new 4.0-litre twin-turbo V8 in this Flying Spur Speed will be the one and only in all Bentleys, henceforth, including the Continental and the Bentayga SUV.

Bentley’s W12 engine is, sadly, no more, which might well make some older Flying Spurs quite collectable.

The V8 will come in different flavours, of course, and it’s also a hybrid, as is the modern way. Bentley calls the 140kW electric motor attached to the engine an “e-machine”.

Using that machine, the Speed can whisk you around in silent, EV-only mode for up to 81km. With such a stupendous sounding V8 on offer, it’s hard to see why you’d bother, but it’s an option, and the hybrid system is cleverly set up so that the harder you drive, the quicker the battery recharges, so effectively you’d almost never have to actually plug this PHEV in.

With the engine and e-machine combined, you’re looking at a staggering 575kW and 1000Nm, enough to propel all 2646kg of this Flying Spur Speed to 100km/h in just 3.5 seconds.

It might not sound quite as orchestrally moving as the big, sassy W12, but it’s still a hell of a replacement, as it is, in fact, “the most powerful Bentley engine ever”. That will do nicely.

Unlike the Mercedes-AMG C63, BMW has kept the M5’s eight-cylinder heart and this has proven to be a good decision. 

The 4.4-litre twin-turbo petrol engine has been optimised with “a cross-bank exhaust manifold and optimised oil separation”, says BMW.

The V8 spins to 7200rpm though it isn't a screamer, outputting a full-bodied 430kW (5600-6500rpm) and 750Nm (1800-5400rpm).

Augmented with a transmission-mounted 145kW electric motor that can produce up to 450Nm, thanks to pre-gearing, maximum combined outputs are 535kW and 1000Nm. 

Weight blunts punch, though, so despite nearly 100kW and 250Nm more, the new M5 is a tenth slower to 100km/h than its predecessor (claimed), at 3.5 seconds for the sprint.

You can thank a 220kW/tonne power-to-weight ratio, worse than the old car's 233kW/tonne figure. The new G90 claws some time back with brute force, hitting 200km/h in just 10.9 seconds and goes on to a limited top speed of 305km/h.

You can choose from five powertrain settings, starting with 'Electric' and 'Hybrid' for everyday use, while 'eControl' lets you store battery power for urban use.

'Dynamic' provides the best balance, says BMW, while 'Dynamic Plus' is like a qualifying mode. Think maximum combined punch for up to 10 minutes, at which point you’ll have drained the battery. 

Driving in pure electric mode, the take-off can be a little jerky but the quietude and decent power make it pleasant. Power sources are combined expertly in Hybrid and giving it some stick in Dynamic is more than enough to make your passengers feel queasy.

So, if you were very careful to use your 81km of EV-only range, as often as possible, and you drove very slowly and treated the accelerator pedal with great care, you might, possibly, achieve the Flying Spur Speed’s claimed fuel-economy of 10.7 litres per 100km. 

That’s the great thing about hybrids like this, they are theoretical fuel misers of the highest order. But if you aren’t careful and you care more about enjoying that twin-turbo V8 engine you’ve paid so much money for, you’re never, ever going to get it under 15L/100km, and you’ll quite likely exceed 20L/100km, as we did, with ease, by driving it around a track all day.

Theoretically, again, this Bentley will emit just 33 grams of CO2 per kilometre. 

Electric-only range is rated up to 69km in WLTP testing, but the 18.6kWh battery is more likely to give you around 60km in real-world driving. It can be topped up in about two hours using an 11kW AC charger, or overnight on a three-pin socket. 

BMW includes both Mode 3 (public) and Mode 2 (home) charging cables with the M5. 

The M5 uses 3.2L/100km of 98 RON premium unleaded in ADR testing, corresponding to just 72g/km of CO2, so it should sail through the first rounds of Australian emissions regulations. 

Indulging in what the V8 has to offer sees that consumption spike, though. An enthusiastic road drive saw the M5 gulp 12.4L/100km, according to the trip computer.

Any car with a whopping 575kW and 1000Nm is going to be interesting, even invigorating to drive, but you’d have to say the smaller and lighter it is, the more excitement, and even fear, you’re going to be faced with.

In the case of the Bentley Flying Spur Speed, you’re talking about an enormous, and enormously luxurious and comfortable, sedan that’s designed to carry more than two people, and weighs a hefty 2646kg.

It’s a limousine powered by a rocket, as I said earlier, but looking at the size, and pondering the weight of it, you really don’t expect too much in the way of thrills. Effortless performance, sure, titanic overtaking thrust, perhaps, but then you read the fine print and note that this Flying Spur Speed can hit 100km/h in 3.5 seconds.

That’s seriously fast in anything, but in a car this big, and filled with as much luxury as a mid-sized super yacht, it feels other worldly. 

Hammering the big Speed around a tight, intense race track feels strange at first and then strangely comfortable. Even sitting in the back wasn’t so much frightening as amusing, as the big Bentley simply slopes through any challenge you throw at it.

Sure, I’d like it to be louder, and you do miss the sound of the old 12-cylinder engine (and Bentley fans in particularly might find its absence upsetting), but the V8 is still throaty enough to please your ears, and it’s important to consider that it’s actually more powerful than the old W12, which is no mean feat.

Compared to the shorter, sharper Continental GT Speed we drove on the same day, the Flying Spur does have a bit more body roll, a bit more pitch and dive under braking from 200km/h, or when accelerating ballistically out of slow corners, but it’s still stupendously impressive for what it is.

And that is a luxury limousine that can turn itself into a race track weapon if you, and your three passengers, want it to. 

The three M5 elements start with daily usability. We trundled out of Bathurst in electric mode, with the adaptive dampers (and other myriad settings) in Comfort. 

The M5 has steel springs, double wishbone front suspension and a five-link rear axle, all of which has been heavily reworked by the boffins at M. Naturally, the ride is firm, though in Comfort the body moves through its motions smoothly. 

The M5 is an effortless tourer, its eight-speed automatic shmoozing through ratios as it climbs and descends steep gradients. Wind and tyre noise insulation is good on coarse chip tarmac, though a bit more burble from the V8 would be appreciated. 

The M5 has nine adjustable parameters to wake it up: 'Drivetrain', 'Energy Recovery', 'Drivelogic' (gear shift aggression), 'Chassis', 'Steering', 'Brake', 'M xDrive', stability control settings and 'M Sound'. Favourite settings can be stored to the wheel-mounted M1 and M2 buttons. 

With the dampers still in Comfort the M5 remains fantastically capable with power delivery from the xDrive mighty rewarding on corner exit. Sport dampers sharpen the experience up further, amplifying the M5’s surprising agility. Thank the rear-wheel steer for this big sedan’s switchback performance. 

Step beyond the limit of grip, brake too late, or get on the power too early, though, and the M5’s mass reveals itself rapidly. It doesn’t help that the accurate steering is devoid of feel. The brake-by-wire pedal is too numb and light, as well, making it tricky to judge grip levels on the road.

Feel is less of an issue on a dry Mount Panorama circuit, where the M5 turns out to be a total pussycat. The all-wheel drive, consistent dynamics, strong brakes and well-tuned stability control make for an approachable but seriously fast sedan.

The responsive transmission will hold gears to redline and is eager on the downshift in its most aggressive setting while tactile shift paddles make commanding ratio changes yourself that bit more engaging. 

Prodigious punch out of corners is matched by the impressive consistency of the carbon ceramic brakes. The M5 pulled up for The Chase every time with minimal fuss, even from above 250km/h.

Similar credit goes to the 285mm front and 295mm rear Hankook S1 Evo tyres which remained consistent and predictable all day despite reaching temperatures over 130 degrees, according to the tyre pressure monitor.

The regular BMW 5 Series range scored a maximum five stars in 2023 ANCAP safety testing but this does not apply to the M5.

The M5 features nine airbags and a host of active safety systems, including auto emergency braking (AEB), blind-spot monitoring, rear cross-traffic alert, lane-keep assist, auto parking and speed limit assist. 

Lane-keep can easily be turned off via two taps but the other systems require more menu navigation, though are mostly unintrusive. A 'Track' mode disables lane-keep, AEB and other systems along with switching the central display off. 

The Bentley Continental GT Speed comes with a five-year, all-inclusive servicing plan as standard.

That sounds good, but stunningly, Bentley still only offers a three-year manufacturer warranty, albeit one with no mileage limitations. That's way below industry standard these days.

The battery that forms part of the hybrid system is, however, warrantied for eight years, or 160,000km.

In Australia, BMW has moved to match other manufacturers in offering a five-year/unlimited kilometre warranty on all its cars. 

Servicing is recommended on a condition basis, with the M5’s multimedia system prompting a visit to the mechanics. BMW offers pre-paid service packs for five years/80,000km at a price of $5059 for the basic offer and $8152 for 'Inclusive Plus', which covers brake pad and rotor replacements. 

It is expensive next to a regular 5 Series but when you consider the purchase price and performance level, the M5’s service pricing is not astronomical.