Toyota makes aero and engine changes for 2023

Significant upgrades have been made to the GR Yaris Rally1 ahead of the season-opener in Monte Carlo


Toyota technical director Tom Fowler has explained the revisions and upgrades made to the GR Yaris Rally1 ahead of the 2023 World Rally Championship season – with revised rear fenders and an uprated engine among the biggest changes.

In the first year of the new hybrid Rally1 regulations, Toyota cleaned up with both the drivers’ and manufacturers’ championships, winning seven of the 13 events courtesy of world champion Kalle Rovanperä and Sébastien Ogier.

But Hyundai was the top performer over the back half of the year, and it has made some significant alterations to its i20 N Rally1 with a more sophisticated rear wing and an extended front lip at the end of the hood.

Toyota, however, hasn’t been standing still either, and its biggest change was revealed on Tuesday as Ogier kickstarted Toyota’s pre Monte Carlo Rally testing.

“The main thing since Japan is an aerodynamic update which we’ve made to the rear fenders which is quite significant in looks,” Fowler told DirtFish.

“Those fighter jet inlets have now disappeared so we have a smooth-sided vehicle with much less pronounced hybrid inlets which is a cooling change basically for the hybrid system but also then of course a help in terms of improving the overall aerodynamics of the car.”

Fowler said that a “combination of factors” had led to this revision.

“A lot of the work that was done on the cooling system [last year] was done theoretically so we didn’t have a hybrid system to measure anything, we just had some numbers as to how much heat is it going to make and how much do we need to cool it by to keep it under control,” he explained.

“And so this was all based on estimations of data that was coming to us from the outside. It was a little bit off in terms of calculations from different aspects from the data we received to the work we did, it was all a bit theoretical and of course for the first season it was a case of going big and make sure we didn’t overheat it, and then now we’ve been able to optimize down from that.”

The new fenders have also been designed in conjunction with a revised rear wing which made its way onto the Yaris at the end of last season.


“The rear wing ties in with the rear fender in terms of now the rear wing works better because we also changed the fender,” said Fowler.

“And of course we had the fender and the rear wing already in mind together last year, but we didn’t bring the fender until this year. They’re kind of a package but you’ve already seen half of it.”

Fowler also confirmed that Toyota has upgraded its engine using its homologation jokers, but described it as “just normal evolution”.

He added: “Everyone talks about peak power but in rally we’re also looking more throughout the whole range so if you talk about peak, no-one’s ever doing anything more than a couple horsepower in terms of peak but what we’ve also looked at is the operating range of the engine because now we have more data about how the drivers can use the hybrid and how they want to use the hybrid.

“It’s a bit clearer. I think this was a discussion before 2022 came ‘what will the engine packages look like because now hybrid is coming?’ Do they need more torque, less torque and so on? So let’s say the characteristics of the engine has also been adapted a bit to match the hybrid that we have.

“In terms of an overall output of the whole system together, it means that we have more consistent torque.”

The driveshaft is the final area to be upgraded for 2023, but Fowler said this wasn’t likely to lead to any performance gain.

“It’s more like a bit of a reliability update, something that we’ve been managing in the background that’s been a bit tricky and we’ve now used the joker to update that so that should give us a bit more safety margin.

“Of course we’ve got some more jokers to use this year so we’re working on those at the moment. What we’ve done now is finishing all the things that were available for ’22.”

Overall, it gives Toyota a package that Fowler is sure will be as good as anybody else’s.

“I think in the base package that we have, I think we’re very confident that the car is capable of taking it to any of our competitors overall,” he said.


“I think we’ve made some steps forward in particular areas already now which will help us in those rallies where we had difficulties [last year] but I think we still have some work to do.

“When I say the base package I believe that what we need to find isn’t something that’s hidden in a joker, it’s not hidden in a big update that we need to do mechanically on the car.

“I think a lot of our weaknesses compared to our competition, stages or rallies where we’ve had a deficit to our competition, is more about setup, about strategy and about how to use the tires that we have available for those rallies.

“In terms of the physical car I have full confidence – exactly how it’s configured using all the tools available, I believe we’ve made steps forward but we still have some more work to do.”