BMW M5 vs BMW 420i

What's the difference?

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.

The BMW 420i is a terrific car if you're after a bit of style and sophistication. Not everyone will warm to your car's nose, but if you get it de-chromed, like this white one, it really does look pretty good. It's a car that uses very little fuel, moves along smartly and is brimming with a decent amount of tech, even if it could do with a bit more safety gear at this price. 

I reckon this car is settling well into the automotive landscape and ignoring it because of a few loudmouths think the grille is too big would be a terrible waste.

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.

The internet exploded when it became clear the big kidney grille was for real. To be fair, BMW did itself absolutely no favours by ensuring the photos of the 4 Series made the twin grille look Easter Island statue sized. 

And it persisted in doing them naked, without number plates to break up the look. In the flesh, it all works, the nose is striking but not completely overblown. 

BMW coupe elegance reigns supreme in profile, however, with excellent proportions, and even in base form the wheels are the right size. The slim tail-lights and sculpted tail complete the look. It's a car I think most people love looking at. Hardly anyone mentioned the grille.

The cabin is excellent, as are all of the newer BMW interiors. It's not really a base model, given the price, but the mix of Alcantara and synthetic leather is very pleasing. 

The big screens for the media and instruments headline the cabin with high-tech style and while it's not avant-garde, it's sharp and feels premium, which is just as well.

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.

As a sports coupe, it's hardly a practical all-rounder but it's not a squishy 2+2 either. The rear seats are sculpted for maximum headroom and have the added bonus of holding onto rear passengers. 

Six footers won't be super-comfortable but it's bearable for short trips. There are two ISOFIX points back there, too. 

The front seats electrically fold out of the way for ingress and egress, but it's not an elegant process.

Front-seat passengers score two cupholders and bottle holders in the doors and a black hole for your phone and its wireless charging pad.

The boot takes an impressive 440 litres and the rear seats split and fold like good little soldiers.

The 420i starts at $71,900. That's a fair bit of money, I think you'll agree.

You get 19-inch wheels, a 10-speaker stereo, LED headlights with auto high beam, head-up display, power front seats, lighting package, auto-parking with reverse assistant, synthetic leather and Alcantara interior, 'Live Cockpit Professional' (fully digital dash), wireless phone charging and digital radio.

The massive 10.25-inch touchscreen may be smaller than the 12.3-inch digital dashboard, but it still looks huge. BMW's Operating System 7.0. is a cracking set-up, and you can control it via either touch or the 'iDrive' rotary dial on the console. It also has Apple CarPlay and Android Auto. Both of them, wireless. You don't read that every day.

You also get 'BMW ConnectedDrive', with some remote services that last for three years. The subscription includes things like the endearingly weird 'Caring Car' and the far less weird real-time traffic information.

The 4 Series is available in eight colours. 'Alpine White' is the only freebie while 'Black Sapphire', 'Arctic Race Blue', 'Portimao Blue', 'San Remo Green' and 'Mineral White' are $1538 each (or part of the 'Visibility Package'). 'Tanzanite Blue' and 'Dravit Grey' are a hefty $2962.

My car for the week had the $6300 Visibility Package (metallic paintwork, sunroof, BMW Laserlight, Ambient Light, which is worth it for the amazing Laserlights alone), the $2860 'Comfort Package' (lumbar support, electric boot, heated front seats, 'Comfort Access' with 'BMW Digital Key') and an $800 black pack. All this took the price to $81,860.

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.

The 420i’s 2.0-litre turbocharged four-cylinder, codenamed B48, spins up 135kW/300Nm. Driving the rear wheels through an eight-speed ZF automatic transmission, you'll go from zip to the 100km/h mark in 7.5 seconds, which is brisk, if not staggering.

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.

BMW's official combined-cycle figures seem to be slowly moving towards reality. The 420i's sticker figure of 6.4L/100km was met with an indicated 6.8L/100km, which was excellent going for almost exclusively suburban and urban running. 

It's a solid result, but being a BMW, it's premium unleaded only for its 59-litre tank.

With my generally unsympathetic (but not psychopathic) right foot, that means a real-world range of over 800km between fills.

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.

One of the main things that sets a BMW sedan or sedan-based coupe apart is that they're good everywhere, except perhaps in quicksand. 

As the platform has matured and BMW's persistence with run-flat tyres has yielded improvements in tyre construction, the 3/4 Series platform (and many others - the internal name for the platform is CLAR) has once again become the benchmark for ride and handling.

For some people reading this, that's a lot of blah blah blah but the main point is, it's a terrific thing to drive whether you're dawdling along in traffic, dealing with traffic calming or bombing down your favourite deserted road.

The Bridgestone tyres on the 420i aren't as ultimately grippy and sticky as the alternative rubber on the 430i but they work well in town and are quiet on the 80km/h roads so prevalent in Sydney. 

The steering is absolutely lovely, providing just the right weight at any given speed and throwing in the road feel to inspire confidence.

Ride around town is compliant but with the whiff of fun if you decide to push things outside of the city. 

Its capabilities are still more than worthwhile day-to-day, however, because the way it handles the need to duck in and out of spaces in traffic is extremely handy.

The 2.0-litre four-cylinder is as smooth as rival Audi's. It doesn't sound like much (with a few vestigial pops in Sport mode) but it's certainly got the power to get you out of sticky situations and a transmission that's willing to play ball, whether in Sport or Normal.

Without the adaptive suspension of its 430i and M 440i brethren, this is a very smooth, easygoing sports coupe, with just enough sportiness to keep you interested, if you're that way inclined.

The 4 Series comes with six airbags, ABS, stability and traction controls, forward AEB, forward collision warning, lane-departure warning, reverse cross-traffic alert and reversing camera.

The 4 Series hasn't been tested by ANCAP or Euro NCAP and the 3's five-star rating can only be a guide because of the very different structure of the 4. 

Sports cars rarely fare well in the sometimes complex rules so carmakers tend to keep them away from the clutches of crash testers.

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. 

BMW offers a ho-hum length of three years and 100,000km of warranty coverage. Mercedes has gone to five years so one wonders why BMW (and Audi) hasn't joined its German rival.

Servicing is entirely reasonable at $1650 for a five-year/80,000km package that covers the 12 month/16,000km servicing regime. 

At $330 per service, it includes things many carmakers don't, such as brake fluid and spark plugs. 

You can go full noise with the 'Plus Package', which costs $4500 and chucks in brake pads, rotors and even windscreen-wiper replacement. That doesn't seem like terribly good value to me unless you drive like a lunatic.