Why longer wheelbase cars could be the F1 trend in 2019
Formula 1's top teams could converge towards longer wheelbase concepts with their 2019 designs as an unintended consequence of a higher fuel allowance.
In a bid to allow drivers to push harder for longer in races, rather than fuel save, a rule change has been introduced for this year to increase the fuel limit from 105kg to 110kg.
The extra five kilos should help minimise fuel saving at some of the marginal races, and help rid F1 of the lift-and-coast tactics that both drivers and fans hate so much.
But the extra fuel does not come without some downside, and if teams want to use the maximum amount possible, they will need to increase the size of their fuel tanks – and that means taking up some of the valuable real estate space in the middle of the car.
Teams cannot simply make their fuel tanks taller, because F1's technical regulations are strict that fuel must be kept no more than 400mm from the longitudinal axis.
The only solution then, with FIA rules stipulating a specific location in the centre of the chassis, is a longer fuel tank, which means either trying to cram in the components that sit behind the old fuel into a smaller space, or going longer.
Last year, there was a significant different in the wheelbase concepts of the top three teams.
Red Bull was the shortest at 3550mm, with Ferrari coming in at 3621mm (both were an increase on 2017), while Mercedes had stuck with its 3726mm length.
Mercedes will be likely reluctant to go longer with its car, having satisfied itself to make no change for 2018. It may well try to simply better package things at the rear of the car.
And even if the team has to increase the length of the car itself, it could still opt to stick with the same wheelbase so it heads in to 2019 with a known concept.
For Red Bull and Ferrari, however, there is some room to go longer – with estimates suggesting that packaging another kilogramme of fuel will require an extra 7mm. That means teams could be forced to go more than 30mm longer – and some may choose to go for as much as 50mm.
The other factor that will come into play is that if teams are forced to extend the wheelbase of their car, that may tempt them to go down the Mercedes route totally, and go very long.
Mercedes has long been convinced about the benefits of a longer car, with the extra body surfaces that are able to generate downforce outweighing the extra weight and lack of agility in slow speed corners.
Speculation coming out of Ferrari has hinted that it may well have been tempted to go longer again this year. This is the result of a potentially longer transmission to move the engine away from the rear wheels – which has helped free up the possibility for a radical rear axle.
If Ferrari has gone down that route, then to help comply with the regulations (because the car's weight distribution is defined by the FIA) it will likely need to have to move its front wheels forward.
Doing that could then free up new ideas for some more aggressive sidepod solutions, which is an area where Ferrari has led the charge in recent seasons.
Finding downforce and aerodynamic efficiency here will be even more important now that the 2019 front wings are less efficient and the bargeboards are lower and longer.
There may for some, however, be a totally different approach to the new fuel factor though – and that could be to ignore the extra allowance.
Even though fuel has been marginal at some races, there have been plenty of times when teams actually under fill so they benefit from running a lighter car in races.
With 10kg of weight worth an average of 0.3 seconds per lap, there will be an obvious performance incentive not to fill the car up to the maximum if you think performance will not be impacted.
It won't be suitable for all races, but could there be an inherent advantage at some races from having a shorter car with a more compact fuel tank to run lighter? Or is the downside that performance would be compromised too much at those events where extra fuel is needed?
The other factor that needs to be weighed up is that the new aero rules for 2019 are going to result in higher drag car – which in simple terms means that more fuel needs to be burned off to get up to top speed on the straights.
The risk of not having the full fuel allowance is that you get things dramatically wrong. That could leave a team not only on the back foot, but potentially in need of all-new car.
Sebastian Vettel, Ferrari SF71H
Photo by: Jerry Andre / Sutton Images
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