Over the years, we have seen some pretty remarkable engines in MotoGP. Whether it be Honda’s iconic RC211V’s V5 engine during the 990cc days or its two-stroke predecessors known for their paralysing speed, often to the detriment of its pilots.
The point is, we’ve come a long way from the early experimental days. Many configurations have perished except for two, which have stood the test of time. The Inline-4 and the V4 configuration.
Although the norm over the years has been the Inline 4, we saw a shift towards the V4 counterparts in recent years, with the European outfits of Ducati, Aprilia, and KTM leading the charge.
Before we dive into the reasonings behind this shift, let’s take a closer look at the current rules and regulations around MotoGP engines.
The regulations
As it stands, engines in MotoGP have a maximum capacity of 1,000cc, with four cylinders either in a V or an Inline configuration at a maximum bore size of 81 millimetres. Every manufacturer has a six-gear transmission.
Before the season opener race, every manufacturer must finalise their engine specifications to the governing bodies to prevent any modifications and development for the rest of the season. Ducati recently faced a conundrum in deciding between its 2024 or 2025 engine.
Given the eight-engine-per-season limit, there is no room for errors, as any mistake would translate to a season-long ordeal. But here’s the twist: The revised concessions system in 2024 allows for more flexibility in engine developments, but only for poorly performing manufacturers.
Based on the constructor standings, the concessions systems place manufacturers on a tier list from A to D, whereas struggling outfits can benefit from additional test days, more engines, or wildcard entries. Although helpful, being on the latter tier of the concessions list is the last thing that manufacturers want.
Battle of the Fours
The longer crankshaft of the inline-four, which increases the moment of inertia, offers superior handling, making the bike more stable through corners as any unwanted rotation is ironed out. The rider can maintain a more stable and predictable U-shaped racing line as the compact design also allows for better mass centralisation.
Think of Alex Rins’ butter-smooth riding style on the beloved Suzuki.
Inline fours typically feature fewer moving parts compared to their V-four counterparts, meaning that on paper, they should be more reliable.
But despite their strengths, inline-four engines generally produce less top-end speed than V-four configurations, which is a significant disadvantage on circuits featuring long straights such as Mugello, where KTM once clocked a top speed of 366 kilometres an hour.
The longer crankshaft and wider engine design also contribute to increased friction and vibration, which reduces overall efficiency and makes it challenging to achieve high horsepower figures without encountering performance issues.
The twins
Excelling in power output, V-fours can thank their shorter and stiffer crankshaft, which allows for higher RPMs and straight-line speed.
Pilots of the twin, especially Brad Binder and Pedro Acosta, often utilise this speed advantage, making up for the shortcomings in cornering by employing a more V-shaped racing line, allowing them to get back on the power much earlier.
The V-four’s profile is also inherently narrower, offering better integration of aerodynamics as Ducati has done in the past, opening the floodgates for the aero era of today.
However, the shortened crankshaft and lower moment inertia of the V4 engine could result in a machine that is more sensitive and demanding to ride. Its mechanical complexities could also post problems, especially in terms of cooling, where Aprilia has struggled with in the years prior.
Upcoming years
For 2027, MotoGP’s engines are set to be reduced from 1000cc down to 850cc in line with the International Motorcycling Federation’s (FIM) bid to reduce speed and costs while promoting safety and consumer relevance.
Although four-cylinder engines will remain, their characteristics will be drastically different, igniting the nightmarish memories of MotoGP’s previous switch to 800cc engines in 2007. A regulation change which lasted for five agonisingly long years where wheel-to-wheel racing was made much more difficult via the smaller engines.