There's never been a better time to buy an M3 or M4 and our guide will make sure you're fully clued-up on BM's twin-turbo twins. Words: Elizabeth de Latour. Photos: BMW, Patrick Lauder.
Buying and tuning guide F8x M3/4
Our guide to the turbocharged M twins.
INTRODUCTIONWe're coming up to five years since the M3 and M4 were launched and, with the G8x replacement models just around the corner, if you've ever fancied one of these turbocharged M offerings now is the time to start thinking about a purchase. Prices have been dropping hard and fast and while they still have a fair way to fall, there are countless cars out there to choose from and, if you shop smart, you can grab yourself a real bargain.
The M3 and M4 were launched simultaneously in the UK in June 2014, with the Convertible following in September. The F8x M3/4 was a big deal for BM because it was the first turbocharged M3 and it was also the first time that BMW had split the saloon and coupé model designation. There was method to this madness, though, as even numbers have historically been used for BMW's coupé models (6 Series, 8 Series), which were the sportier versions of their saloon counterparts, so it made sense. Everyone knew that the move to turbos was on the cards and we'd all been seriously impressed with the F10 M5 but, even so, the thought of a turbocharged M3 was something that took some people a while to get their heads around. Rather than going for a big increase in power, which has always been BMW's MO when it come to new M cars, here the focus was on weight saving over the E9x model and using the massive torque advantage of the S55 over the S65 to generate the increased performance over the outgoing model.
The S55 is a 3.0-litre twin-turbo straight-six derived from the N55 but with a raft of changes and, most noticeably, two turbos instead of one. Peak power is 431hp , just 11hp up on the S65, but it's available from 5500-7300rpm meaning you hit peak power sooner and have it available for longer. The biggest difference is torque and here the S55 puts out a hefty 406lb ft – 111lb ft more than the S65 – and it's available from 1850-5500rpm. With the standard six-speed manual gearbox the M duo can crack the 0-62mph sprint in just 4.3 seconds while the optional DCT gearbox drops that to a frantic 4.1 seconds, making it one of the fastest BMWs ever produced at the time. The move to a smaller capacity turbocharged engine also brought with it a significant improvement in fuel economy and efficiency, with the DCT-equipped models able to achieve 34mpg on the combined cycle, with a 194g/km CO2 figure, a significant improvement over the E9x M3, making it a much cheaper car to own and run.
The S55 features two fast-responding single-scroll turbos with a chargecooler, high-precision direct injection, Valvetronic and double-VANOS, a closed-deck crankcase, a twin-wire arcsprayed coating in place of cylinder liners for reduced weight, and a forged crankshaft, along with a lightweight magnesium sump with a specially baffled cover to prevent oil starvation. The stock six-speed manual gearbox is smaller and lighter than that of the E9x M3, saving 11kg, and there's a carbon fibre propshaft, replaced with a steel item from late-2017.
Lightweight aluminium chassis and suspension components, such as the control arms, wheel carriers and subframes save 5kg over conventional steel items, while a carbon strut brace helps to increase front end rigidity. Forged 19s were fitted as standard as was Adaptive M suspension, the M3 Saloon received a carbon roof for the first time, and the front wings and bonnet were aluminium to further save weight – a manual M4 weighs 80kg less than a similarly-equipped E92 M3.
Alongside the base M3 and M4 models, BMW has added a number of additional versions to the line-up over the years. The first of these was the M4 GTS, which went on sale in March of 2016 with a cool price tag of £120,770; production was limited to 700 cars over a single year and just 30 of these came to the UK. For the GTS the S55 received water injection and this enabled BMW's M engineers to increase power to 500hp while torque rose to 443lb ft, enough for a 0-62mph time of just 3.8 seconds, making it the fastest BMW ever produced. It came with the M DCT gearbox as standard and featured a carbon bonnet and front splitter, carbon seats, lightweight centre console and a rear seat-delete while a roll-cage, six-point harness and fire extinguisher were a no-cost option. There was also a titanium exhaust system, high-rise rear wing, carbon diffuser and carbon ceramic brakes. Unique forged alloys measuring 19” up front and 20” at the rear were fitted, along with three-way M coilover suspension and OLED rear lights.
In 2016 the Competition Package was added as an option and brought with it a 19hp power hike for a total of 450hp, specially-tuned Adaptive M suspension with new springs, dampers and anti-roll bars, and the Active M Differential and DSC were tuned to match the chassis upgrades. Exclusive forged 20s were fitted along with special lightweight seats, seat belts with M tricolour stripes, a louder M sports exhaust with black tips and high-gloss Shadow Line exterior trim.
2016 also saw the launch of the M3 30 Jahre Limited Edition model, introduced to celebrate 30 years of the M3 and limited to just 30 cars for the UK. The car came with the Comp Pack and received a selection of additional equipment, including Individual Frozen silver metallic paint, High Gloss Shadow Line trim, black chrome tailpipe trims for the M sports exhaust system, as well as a carbon fibre front splitter and trims, mirror caps, rear diffuser and a carbon fibre rear spoiler. The model also featured exclusively designed M gills in the front wings bearing the logo “M3 30 Jahre” and the same logo on the door sills. It also came with full leather Merino trim in bi-colour black/Fjord blue with contrasting stitching and featured a very high standard spec, which included the carbon ceramic brakes.
In October 2016 the limited edition M4 DTM Champion Edition arrived, with 200 cars being produced to celebrate Marco Wittmann securing yet another DTM driver’s title at the season finale at the Hockenheimring. This model received the same water injection as the M4 GTS, making 500hp and 443lb ft, and was available in Alpine white with M tricolour stripes and highlights, a carbon splitter and canards, mirror caps, side skirt attachments, rear diffuser and spoiler. Inside there were M carbon bucket seats finished in Alcantara and Merino leather, an Alcantara steering wheel and white roll-cage. It also received the OLED rear lights from the M4 GTS, carbon bonnet and titanium exhaust along with matt Orbit grey 19” and 20” wheels, carbon ceramic brakes and three-way coilovers.
In 2017 the M4 received a facelift, which added LED headlights as standard (added to the Saloon in March), 3D LED rear lights, new-look illuminated M4 emblems on the front seats and double stitching on the instrument panel.
The M3 and M4 CS were both launched in 2018 and sat between the Competition Package and GTS, delivering a more hardcore experience without going all-out and being completely unusable on a day-to-day basis. The S55 was tweaked to 460hp with 443lb ft of torque and the model was equipped with a sports exhaust, M DCT gearbox, and the chassis setup was very similar to that of the Competition package but tweaked to be even more sporting. Unique, 10-spoke forged wheels in Matt Orbit grey, measuring 19” up front and 20” at the rear, were fitted and the CS models received a whole host of carbon goodies including the vented bonnet, three-part front splitter, unique boot spoiler and diffuser. Inside, there were Competition seats in black and Silverstone leather, Alcantara throughout the cabin including on the dashboard, centre console and handbrake lever and the sills also featured the M3 CS logo while standard equipment included Harman Kardon surround sound and the Icon Adaptive LED headlights. The CS came as standard in Alpine white, while optional colours included San Marino blue metallic, Lime Rock grey metallic, Frozen Dark blue II metallic and black Sapphire metallic.
The final special model to be launched was the M4 Convertible 30 Jahre, which arrived in 2018 and was generously equipped. It came with the Comp Pack, was available in Macau blue and Mandarin II – similar to Dakar yellow – colours, has High Gloss Shadow Line trim, 20s in Matt Orbit grey, two-tone full leather, carbon trim and 30 Jahre Edition lettering on the sills and headrests.
M4 DTM Champion Edition. M4 30 Jahre Convertible
WHAT TO PAY
While you can't ever really call any £20k+ car cheap, looking at how far M3/4 prices have dropped you can certainly call it good value for money and even a bit of a bargain, considering just how much performance you're getting for your money. The cheapest M4s start at around £25,000 – for that you can expect around 70,000 miles, maybe DCT and not much in the way of options, but what a lot of car for your money. M3s are a little more expensive – we found a manual with 75k on the clock for £26k but, realistically, you'll need to spend nearer £29,000. Once you're over the £30k threshold, mileages begin to drop considerably and for around £32,000 you can pick up a 35k mile example and at £36,000 mileages drop to around 20k and below. For M4s, £30k will get you a car with under 50,000 on the clock and around £32,000 will get you an Approved Used car with under 30,000 miles. The cheapest convertibles, meanwhile, start at around £30k and mileages are generally lower than those of coupés and saloons – you can pick up a manual M4 Cab with 6200 miles for £32,500, for example. Comp Pack M4s appear at around the £36k mark, M3s at £38,500 and then, getting into the more expensive limited edition models, you can pick up a 2018 M4 CS with 1400 miles on the clock for £60,000 – that's a drop of almost £30,000 in one year – or an M3 30 Jahre with 9k on the clock for £62,000, a drop of £20,000 in two years, and we found an M4 Convertible 30 Jahre for about £57,000, which works out at a £20k drop in about six months.
The mighty M4 GTS The M4 CS
WHAT TO LOOK FOR
Honestly, not a lot. Admittedly even the oldest examples aren't all that old and haven't covered that many miles, but that's still long enough for problems to appear and there just haven't been that many. Minor stuff includes head and rear light condensation, some interior squeaks and rattles, the carbon roof lifting due to poor quality brackets, stones getting caught in the brake guards, and cracking seat badges. The biggest problem is with the crank hub, which can spin and will result in some engine damage or, in the worst case, complete engine failure. The number of incidents is very small, but it can and does happen – we've read about owners who've had it happen within days of having the engine repaired from a previous incident and it seems that whether stock, modded, manual or DCT, it can happen to anyone. BMW changed the bedplate design later on but there are reports of spun crank hubs on even low-mileage 2018 cars. Some companies have engineered solutions so it's definitely worth doing your research, having a proper read of all the information out there and being aware of it, but don't let it put you off buying an M3 or M4.
While there are an awful lot of different M3 and M4 models to choose from, truth be told we'd probably be more than happy with just the standard car – it's so quick, looks great, handles brilliantly and is everything you could possibly want, honestly. You're never going to drive one and be disappointed, trust us. We'd also choose M3 over M4 – the M4 is better value, but we just love the narrow body and wide arch combo of the M3, it looks more muscular and, to our eyes, more visually appealing. Whatever we were buying, though, we'd want to spend a little bit more in order to get a nicely-specced car in the right colour; M3s and M4s are quite spec-sensitive and there are definitely some must-have options. For us, it's got to be DCT – the manual's good, but we just prefer the feel of DCT, plus it's faster and better on fuel, so it ticks all the boxes really. Carbon interior trim would be very high on our list as it looks a million times better than any of the other trim options; we'd want HK audio, possibly HUD and we'd strongly consider Full leather, as it makes the cabin look and feel so much more special.
What about the Comp Pack, is it worth it? We'd say it's very much a case of personal preference – the ride will be harsher, but at the same time the stock car is known for being a bit twitchy while the Competition suspension revisions make it feel a bit more connected to the road, which is obviously a good thing. A less good thing is the seats – they look cool with those cut-out portions, but they don't have lumbar support, so if you have back problems or tend to get back pain when sitting down for long periods, that could be a deal-breaker for you. As for the limited edition models, if you've got the means then they are serious bargains when you consider how much money they've dropped in such a short space of time – it's so scary that we actually feel a little bit sorry for the original buyers. Either an M4 CS or an M3 30 Jahre would definitely be a nice thing to own, but at £60k you'd feel like you're standing on the edge of a depreciation cliff, and it's a long drop, so we'd go in with our eyes open on something as expensive as that.
The S55 has so much tuning potential that you don't need to spend a lot of money to get a lot more power out of it, but you certainly can if you want some truly monster performance. Step one will be a JB4, which will give you about 480hp, or a remap, which should give you slightly nearer 500hp. The next step will be some downpipes, either cat-less ones or ones equipped with high-flow cats, either of which will eliminate the immediate restriction right after the turbos in the exhaust system, increasing volume, power (to the tune of 20-30hp) and improving turbo response. Uprated charge pipes are also a worthwhile addition as the stock items can start to break when confronted with increased boost levels. An uprated chargecooler from someone like CSF would be a worthwhile addition as it will keep intake temps lower, giving you more power, and can be combined with an uprated or even additional heat exchanger for even more cooling. Water/meth injection is also something to consider but that's only really worth looking at once you're really ramping up the power with some uprated turbos. There are lots of options out there, like Schmiedmann's Stage 2 upgrade, as fitted to our 700hp M4 cover car this issue, which will really take your M3 or M4 to a whole other level of performance.
S55 has huge modding potential
With adaptive dampers standard across the board, you're limited in terms of what you can do with the chassis. In terms of the suspension, if you're interested in absolute driving dynamics, want adjustability or are planning a hardcore track build, then a set of coilovers from someone like BC Racing, Bilstein or KW will give you a level of adjustment that the stock setup won't be able to match and, likewise, if you're looking to get seriously low then coilovers or air are going to be your two best options. If, on the other hand, you're going to be spending most or all of your time using the car on the road then we'd stick with the stock adaptive damper setup because it's really good. We'd be more than happy to get some lowering springs to go with it – Swift, Eibach and AC Schnitzer all get good reviews and BMW offers a height-adjustable spring kit as parts of its M Performance range.
Obviously this is all very personal but our first port of call would be getting rid of the chrome trim that BMW decided would be a good idea and replace it with gloss black or carbon elements from someone like MStyle. Carbon splitters look great but can but a nightmare if you're using your M3 or M4 as a daily and are worried about speed humps, in which case a pair of carbon corner splitters would be a better option, and you can also add carbon upper bumper elements, aka 'fangs.' Carbon side blades and mirror caps are always a good option as is a nice boot lip spoiler but if you'd rather splash out you can pick up a CSL-style carbon ducktail boot lid from MStyle from £2500; we also love a diffuser so we'd definitely be picking one up and there are plenty to choose from. If you really want to push the boat out then the holy grail is a genuine GTS/ CS vented carbon bonnet, which will set you back almost £5k, and that's without paint. And if you really want to go nuts, then how about a set of those OLED rear lights? They will cost you… about £8000. Really. Well, at least you're not going to come across too many other cars with them fitted.
As for the interior, you can go mad with the carbon, including door pulls and DCT gear selector, get yourself an Alcantara M Performance steering wheel and then there are things like a GTS/CS-style Alcantara lightweight arm rest, extended shift paddles and little things like changing the start-stop button for red (or blue) and beyond that have a look at our cover car – we're talking rollcage, lightweight seats, the works really.
There are loads of styling options out there for both cars. The stylish M4 Convertible
In terms of performance for your pound and bang for your buck, the M3 and M4 are hard to beat. They're both seriously fast and incredibly capable machines out of the box, their modding potential is off the scale and the sky is quite literally the limit when it comes to tuning both of these M cars. While they've not finished depreciating just yet and prices still have further to fall – especially when you're talking about the more expensive examples and limited edition models – the cars positioned at the lower end of the price spectrum could be purchased and enjoyed without fear of losing too much money as the depreciation curve starts to level off. And if you don't care about depreciation then none of that matters as you'll be having too much fun to care. As an all-round performance package that's practical enough for daily use, capable enough to take on track, and guaranteed to get your heart racing whenever you get behind the wheel, the M3 and M4 are very hard to beat and either one makes for an exceptional used buy.