Why Toyota’s testing focused on tyres ahead of Rally Croatia

There was one recurring word running through Toyota’s official Rally Croatia preview – tyres, tyres, tyres. Kalle Rovanpera was the only interviewee not to mention it – the Finn focused on palming off any suggestions he was under pressure as the current World Rally Championship leader.

But why the sudden fuss over those four rubber tyres that are supplied the same to every WRC team and crew?

Rally Croatia is the first traditional asphalt round since Pirelli rejoined rallying’s top tier three months ago in Monte-Carlo.

While crews tackled tarmac terrain on Rally Monte-Carlo, the conditions in Croatia will be altogether different. In fact of the four tyre compounds offered by Pirelli on round one, only the soft returns in Croatia.

Pirelli’s “P Zero Soft” is sandwiched between hard and wet weather compounds this weekend.

Even though Toyota was testing with upgraded front aerodynamics on its Yaris WRC, team principal Jari-Matti Latvala stated the team’s six-day test focused on Italian rubber.

“Of course, we know the car well now,” said Latvala, “and it is not so easy to keep making big steps with the set-up, so our main focus has been on how to get the best out of the new Pirelli tyres.”

Toyota comes into Rally Croatia benefiting from its strong showing on Rally Monte-Carlo. Bodywork changes around the Yaris WRC’s front arches and winglets should increase the car’s front downforce, grip, and turn-in; giving its drivers added confidence on Croatia’s precise asphalt stages.

It’s a prospect reigning world champion, Sebastien Ogier, is clearly excited about:

“It has been a long time since we had a full asphalt rally like this one, and the Yaris is a great car to drive on asphalt, so I’m sure it will be fun.

“From what I’ve seen so far, the roads could be quite challenging, maybe a bit dirty and narrow in places, so I’m sure there will be plenty of action ahead of us.

“The pre-event test was very important because we have new tyres this season and this was the first chance to drive the slick tyres on dry asphalt.

“I did a lot of runs, trying all of the different combinations of tyres and trying to be ready to make the best choices during the rally.”

Experience of different hard-soft-wet combinations will be crucial when it comes to having confidence from the first corner of every stage in Croatia. Obviously, this is all weather dependant with conditions over Rally Croatia’s 20 stages potentially completely different to that on Toyota’s pre-event test.

Understanding how the new tyres react to suspension and differential changes would also have been an important facet of pre-event testing. Combine this with how grip levels and car balance change with different tyre pressures or different compound combinations; there is plenty for engineers to get their heads around.

New aero, new tyres, never-seen-before stages… Croatia really is a step into the unknown for Toyota.

The Finnish-based team will have its dataset from testing ready and waiting when the action gets underway this Thursday.

As for Elfyn Evans, who is more than capable of a strong appearance on asphalt, he expects Rally Croatia to demand an “adaptable” approach through the stages.

“The stages look quite mixed, with some wide fast parts and some very narrow bumpy parts, and there could be quite a lot of cutting.

“So it looks like we need to be quite adaptable to the different surfaces and different character of stages that we’ll face.

“We don’t have masses of experience with this car on dry asphalt or with the Pirelli tyres, so in testing we were trying quite a few different settings.

“But the feeling in the car was generally positive straight away from the first runs.”

Whatever conditions are present in Croatia this weekend, Pirelli will be hoping for an end to the problem of punctures that hit several crews in Monte-Carlo.

Ott Tanak was the biggest victim on the WRC’s opening round. His double puncture had him leaving the French Riviera without a single championship point. Punctures on Rally Monte-Carlo’s mountain passes is no new phenomenon but if punctures persist in Croatia it won’t be long before teams start to raise eyebrows, especially with asphalt featuring more than usual in the WRC this year.

Photos courtesy of Toyota Gazoo Racing WRT