BMW M4 vs Audi RS5 vs Lexus RC-F: Which one has the lowest running costs?
Their pricetags might be very similar and they appeal to the same buyers, but these three high-performance coupés go about their business in rather different ways, with three distinct engine- and driveline configurations on offer. Do these differences result in meaningful changes to the running costs? We looked at the numbers for the BMW M4, Audi RS5 and Lexus RC-F to find out.
Can you pre-determine your car’s running costs?
When considering a car’s running costs, it’s important to look at it over the full life-cycle. This allows third or fourth owners of older cars to get a clearer picture of possible future expenses, and it helps first owners to determine at what age their cars may become too expensive to run.
There are certain key points which could give an idea of a car’s general upkeep requirements. This includes the length of the service intervals, the cost of replacement tyres and service- and maintenance parts, and the prices of service parts. Seeing as these three cars cost upwards of 1.3-million Rand, it’s likely that running costs will be of lesser concern to new-car buyers on account of the extensive maintenance plans standard on all of them.
For those fortunate buyers, the main concerns would be reduced to depreciation, tyre prices, insurance and fuel thirst, but the second and third owners might want to know just how fat their wallets really need to be to own such a (by then massively depreciated) sports coupé.
Let’s meet the contenders
BMW M4 Coupé (R 1 474 362)
The BMW M4 is due for replacement very soon, but that doesn’t make the outgoing model any less appealing. Even without “Competition” or “CS” added to its name, the M4 is still the hairy-chested brute we’ve come to know, and it has just enough danger and civility mixed into a slinky shape to appeal to drivers of an enthusiastic inclination.
Performance is suitably rapid even in the “entry-level” variant: a 3.0-litre twin-turbo inline 6-cylinder engine sends 317 kW and 550 Nm into a 7-speed dual-clutch gearbox, good for a claimed 0 – 100 km/h dash in a tyre-smoking 4.1 seconds and a speed limiter set (like the Audi’s) at 250 km/h.
Related: Keen to get an idea of the next BMW M4’s styling? Check out our report on the latest BMW 4 Series coupé here.
Lexus RC-F (R 1 385 300)
Similar in concept but very different in execution, the Lexus RC-F is also a rear-wheel drive beast with buckets full of torque – but there’s a naturally-aspirated V8 under the bonnet instead of a turbo six. We’re looking at the normal RC-F here, because the higher-trim “Track Edition” costs an eye-watering R 819 500 more and is no more powerful. That’s enough spare change to buy a spare Corolla and a new Quest for your offspring’s use...
It’s slightly down on torque compared to the M4, but because that torque (530 Nm) is delivered right at the top of the rev range, it unleashes a bellowing 351 kW on the rear tyres courtesy of an 8-speed automatic gearbox. Expect the sprint to 100 km/h to take 4.3 seconds before running on to a governed 270 km/h.
Related: Scaring the Germans – we review the Lexus RC-F.
Audi RS5 coupé quattro (R 1 347 000)
Meanwhile, the Audi RS5 is a different beast entirely, all thanks to all-wheel drive and an added chunk of torque. We’re looking at the (slightly) less expensive coupé version here – the alternative is a fastback 5-door “Sportback” body style with identical outputs.
Where the others put up a show of getting the power to the ground, the Audi just squats, grips, and goes. It’s effortlessly quick in almost any road condition, and registers a 0 – 100 km/h run in 3.9 seconds courtesy of a 2.9-litre twin-turbo V6 engine that delivers 331 kW and 600 Nm into an 8-speed automatic transmission.
Related: Audi Sport’s über-GT: Read our launch report of the Audi RS5 here.
Which one has the lowest running costs?
Purchase price and depreciation
The BMW M4 starts out with a handicap in this department, because it’s the most-expensive car here - almost R 130 000 dearer than the least-expensive (the Audi, itself not undercutting the Lexus by much), which will have a significant impact on monthly instalments.
Initial depreciation is also quite steep (an easy 20% drop from the price of a new M3 in 2019), likely as a result of the imminent arrival of a new model and the presence of higher-performance derivatives in the range. However, at the time of writing, the average retail price of the 2014-model year M4 coupés listed on AutoTrader was still above 70% of its values when new – very strong long-term value retention for a 6-year-old niche-market performance car.
Neither the Audi nor the Lexus has been available for long enough to get relevant data regarding long-term value retention, but we can already make some observations regarding initial depreciation. The Lexus RC-F and Audi RS5 suffer similar initial depreciation, with the Audi losing 25% in two years and the sole Lexus RC-F on our site losing 21% in its first year.
Instalment calculator
*Calculated with to the AutoTrader Car Finance Calculator, with a 72-month finance agreement, 10% interest rate, 10% deposit, and no residual value. All prices listed in this article were accurate at the time of writing, but may change without prior notice.
BMW M4 coupé
List price: R 1 474 362
Instalment: R 24 582/month
Audi RS5 coupé
List price: R 1 347 000
Instalment: R 22 459/month
Lexus RC-F
List Price: R 1 385 300
Instalment: R 23 097/month
Fuel efficiency
Going on official average consumption figures, the BMW M4 wins this round with a claimed 8.3 ℓ/100 km. The Audi RS5 comes close, with a claimed 9.0 ℓ/100 km and the Lexus RC-F quite a way back at 11.2 ℓ/100 km. That’s the one downside of a big V8 instead of a boosted 6-cylinder, but it does compensate with a memorable aural signature that’s easily the most pleasing here.
In real-world conditions, none of them will even get close to these claimed figures, however, as the temptation of unleashing all that power will inevitably lead to mid-teen numbers, if you’re lucky or moderately restrained in your driving style.
Related: Which engines have the best efficiency?
Warranties, maintenance plans, and service intervals
We immediately have to note that the Audi’s warranty only runs for one year, but covers an unlimited distance. The BMW’s warranty provides coverage for two years, but again with no mileage limit. They both have extensive maintenance plans, though, with identical coverage for 5 years or 100 000 km, largely rendering the warranty duration a moot point anyway.
As good as these maintenance plans are, they still pale in comparison to the Lexus’s aftersales package. Its warranty and maintenance plan both provide all-round cover for 7 years or 105 000 km, giving the Lexus the most valuable real-world cover – cars in this class generally don’t cover galactic mileages, being specialist models, so the duration of pre-paid maintenance is more relevant than a distance limit.
Service intervals are determined by the car’s control system in both the BMW and the Audi, but a yearly inspection/brake fluid change is required. Conversely, the Lexus needs a service once a year or every 15 000 km... but remember, for the first 7 years, those services will be on the house.
Related: What is usually covered under a manufacturer’s warranty?
Insurance
All three cars are considered to be high-performance machines, so their insurance premiums are likely to be significant. The Germans are also considered higher theft- and hijacking risks, leading to further-inflated insurance costs. The BMW will however have the highest insurance premiums of this trio, simply because it will also cost the most to replace – that’s its higher sales price coming into play. Lexus grabs a win by default here, but it’s going to be pricey to insure nonetheless.
Also remember that insurance premiums will vary mostly based on the projected mileage to be covered and where the cars are kept and driven, both in the daytime and overnight. Younger drivers or those with prior accident histories will experience additional penalties, due to their higher collision risk. And, if these cars are ever driven on a race track, ensure that the appropriate insurance is in place, as general policies don't cover damage sustained on track.
Related: Top tips to save on your car insurance.
Tyre replacement
Standard tyre prices play a significant part in any running cost evaluation, but it’s not always a given that smaller tyres will be less expensive – if they’re less commonly used, they might be harder to find and more expensive to replace than larger tyres which are in wider use.
The BMW M4 has the smallest standard wheels in this group, with 18-inch rollers which can be upgraded to 19-inchers at extra cost. Its 255/40R18 (front) and 275/40R18 (rear) tyres are surprisingly plentiful in the marketplace, with 16 alternatives starting from about R 1 500 for “house-brand” tyres and running all the way to the R 4 800 mark for premium brands. However, in a car with this kind of performance, you’d be well-advised to rather spend extra on superior rubber.
Next up is the Lexus, which uses 19-inch wheels with 255/35R19 (front) and 275/35R19 (rear) tyres. Availability is better than that of the BMW’s tyres (particularly for the rear tyres), but tyre prices are pitched around the same mark. Owners are advised to shop around, as prices for same-brand tyres in this size vary widely between retailers.
The Audi has the biggest wheels, but uses the same size tyre all round (due to its quattro AWD system). 275/30R20 rubber covers each big alloy wheel, and they are expensive rubber hoops, with prices that start at R 4 370 and run up to R 8 600 apiece. That’s right: a full set of replacement tyres will set you back at least eighteen grand including fitment and balancing, and you have to replace them as a set once they’re worn out – again due to its AWD system...
This result ends up in a draw between the BMW and the Lexus, with the Audi’s pricey footwear placing it at the back of this pack. In mitigation, the Audi’s tyres should last somewhat longer, because it sends the power to all four wheels rather than just to the rear ones – particularly applicable to those drivers with an enthusiastic bent.
Related: How long is a tyre supposed to last?
Verdict
First-time owners will need to weigh up the advantages of each of these cars individually, to decide which criteria are the most relevant. First-time buyers who plan to keep their car for a long time will likely find the Lexus to be more-affordable to run until its maintenance plan runs out: it’s the cheapest to insure (in this group), and if the owner plans to stick to a moderate yearly mileage limit, its higher fuel thirst should be offset by cheaper tyres and lower instalments.
In the long term, the Lexus should also prove less-expensive to maintain, simply because its non-turbo engine has fewer things to go wrong. In addition, it’s backed and manufactured by Toyota, who built their reputation on durability and high-quality offerings. The turbo engines of the German duo will in all likelihood require expensive maintenance once they’re outside of their maintenance plans, which would make them costlier to run in the long term.
However, as far as short-term ownership is concerned, the "lowest running cost" crown will have to go to the BMW, particularly if its owner plans to conduct many long-distance trips in the first years of ownership. The maintenance plan will keep the mechanical bits in order, and the fuel savings and cheaper tyres will offset the higher instalments in this usage scenario. All of which leaves the Audi in third place: it is reasonably fuel-efficient, the cheapest of this lot, and with comparable insurance costs to that of the BMW. Those big tyres are its undoing, though, and will eat up any savings made on the instalments or fuel bills.