Even after 36 years, the Golf GTI is still the hot hatch to beat, not least by rivals from within Volkswagen's own stable. Ever the masters of the shared platform the Audi S3 - even the Skoda Octavia - can trace a bloodline to the Golf, but it's the SEAT Leon, in both FR+ and Cupra R guises, that offers the closest sibling rivalry to the Golf GTI in terms of performance and price.
True, the Leon and Golf are slightly out of sync in terms of vintage and market positioning, but the on-paper similarities are too close to ignore and too tempting not to compare. We'll be unearthing other family feuds over the coming months but for our first we'll explore two branches of the VW family tree, how they've evolved, what they share and how they differ.
In the beginning there was only the Golf GTI. Six generations on, the seminal hot hatch has found a staggering 1.7 million owners worldwide and sealed its place in the four-wheeled hall of fame. Rivals looking to copy the formula have come thick and fast and from all corners of the globe. But VW has created its own in-house competitors too.
Evolved from the Sport model in 2000, the first Leon Cupra shared much with the Mk4 Golf GTI but extracted an extra 29hp from the 1.8-litre turbocharged engine to give 179hp. Never the GTI's high point, the Mk4 was left looking distinctly lacklustre against its Spanish cousin, especially when the 210hp Cupra R appeared two years later. VW responded with a 180hp GTI but SEAT maintained the power advantage, boosting the Cupra R to 225hp.
But with its approach of producing in-house rivals Volkswagen had created a problem. And one that forced it to seriously up its game with the Mk5 GTI, delivering 200hp and, for the first time, the DSG gearbox. The theme continued into 2009's Mk6, available in standard 211hp form with the new EA888 engine and 235hp Edition 35 and 270hp Golf R using the previous EA113 motor.
Meanwhile the Leon has always maintained a power advantage over the equivalent Golf, the second generation Cupra in 2007 launching in 200hp 'warm' (in the Spanish sense!) FR guise and 240hp Cupra. In 2009 the FR got the 211hp EA888 engine, 2010's Cupra R sticking with the 'old' engine and a mighty 265hp for just £675 over the 'basic' three-door manual Golf GTI. As it stands the FR+, as it's now known, undercuts the Golf GTI with which it shares the same 211hp engine by £3,380 - win-win for SEAT either way then, at least on the bang per buck and contributing to the impressive 18,447 FRs that have sold in the UK
Brothers in arms
So what do they share? As a group team, the Golf GTI and SEAT Leon have not just taken the hot hatch fight to other manufacturers, they've established a position of pre-eminence - thanks in large part to a shared vision and exemplary DNA. Both have focused on blending rewarding driving dynamics with accessible performance, and high build quality. And in latter years have led the field in performance diesel engineering too - both GTI and FR brands offer 170hp diesel versions that are hugely popular.
Volkswagen and SEAT are understandably coy about exactly how many components their hot hatches share in common, but despite sharing basically the same PQ35 platform, almost identical engines and plenty of common cabin gear SEAT still employs almost 1,000 development engineers and chassis experts at their Martorell Technical Centre helping to make its Leon look and feel noticeably different from the Wolfsburg-built Golf. And so it will continue when the much awaited Mark 7 Golf GTI and Mark 3 SEAT Leon FR+ arrive soon.
Like most siblings however, once the gloves are off competition is as fierce as ever. Looks-wise there's no escaping the family resemblance - even if you pick a three-door rather than a five-door Golf GTI. Like brothers, the size and stance are remarkably similar, although the SEAT appears marginally more dynamic. The Golf, however, claims truly stunning polished five-hole alloys, a more menacing stare and chrome twin exhaust pipes. Not to be outdone the Leon fights back with a larger boot, a noticeably better spec and more contemporary seating - the Golf's picnic-hamper plaid seat coverings aren't to everyone's taste.
Historically the Leon, with its lower price tag, has offered more for your money - this latest FR+ is not only significantly cheaper than an equivalent Golf GTI, it's also better specced (the standard sat-nav, xenon lights, front parking sensors, DAB radio and cruise control equivalent to around £3,600 of extras on the GTI), pushing the 'real-world' price comparison further in favour of the SEAT. But this doesn't tell the whole story, because VW's GTI fights back with greater kudos, stronger residual values and a fresher design that's effectively a couple of years younger.
Any remaining brotherly love goes completely out of the window once you turn the key, with the Leon FR+ possessing crisper throttle response, lighter steering, quicker braking and what feels like marginally better performance - despite identical official figures. The GTI counters strongly with chunkier steering, a more refined ride, better front and side visibility, smarter cabin design and a more rewardingly racy exhaust note.
Deciding between the two is a real heart-versus-head puzzler, the SEAT's amazing value facing a stern test against the snob value of the VW badge and the fresher Golf package. Like all fraternal fights it's closer and more bitter than most and looks to run and run yet. One things for sure, it proves the point that blood is thicker than water.
Engine: 1,984cc 4-cyl turbo
Power (hp): 211@5,300rpm
Torque (lb ft): 206@1,700rpm
Transmission: 6-speed manual/DSG
Kerb weight: 1,395kg/1,425kg
Top Speed: 145mph
MPG: 38.7/37.7 (NEDC combined)
Price: £10,650 to £23,100
Love it: A real sleeper in subtler colours
Loathe it: Leon Cupra R is even quicker - yet still cheaper than a Golf GTI
Spotted:2010 SEAT Leon FR £13,495
Engine: 1984cc 4-cyl turbo
Power (hp): 210@5,300rpm
Torque (lb ft): 206@1,700rpm
Transmission: 6-speed manual/DSG
Kerb weight: 1,393kg/1,414kg
Top Speed: 149mph/147mph
MPG: 38.7/38.2 (NEDC combined)
Price: £18,000 to £25,320
Love it: Thirty-six years on and it's still the class leader
Loathe it: You could buy two 2009 Leon FRs for the price of a new GTI
Spotted: 2009 Golf GTI three-door £16,150
Photos by Michael Ward