Will the aerodynamic improvements introduced on the hybrid prototypes of BMW and Cadillac at testing in Daytona improve their chances of winning in the 2026 IMSA WeatherTech Championship?

The cat-and-mouse game known as evo updates sometimes lives up to the nickname of “jokers.” Teams make changes that allow them to stay within the guidelines of the rulebook, in this case the LMDh regulations. They try to improve their lap times without getting hit with Balance of Performance (BoP) penalties right out of the box.

Teams emphasize changes are made for better efficiency, handling, and driver performance. But if lap times improve as a result, BoP eventually comes into play with power and weight considerations.

The BMW M Hybrid V8 and Cadillac V-Series.R were making their first official appearance with new bodywork in Friday’s test day at the Daytona International Speedway. The cars underwent homologation by IMSA at the Windshear tunnel in Concord, North Carolina, prior to the test, confirming eligibility for GTP and World Endurance Championship competition. Both manufacturers used some of the five allowed evo updates given to teams for the first generation of hybrid prototypes through 2027.

Cadillac’s statement on the V-Series.R changes noted the “removal of front dive planes and winglets” as well as the “reshaping of the rear wing profile.” While retaining the original design elements to promote the brand, Cadillac’s updates are expected to sustain the relatively high downforce of the V-Series.R while achieving better efficiency on the straights.

The changes at the front of the M Hybrid V8 have appeared previously during tests in Europe. BMW has reduced the large, sideways prototype version of the company’s signature kidney grill openings, which did little in the way of appearance. The openings were tightened up to allow for dedicated air intakes between the outside edges of the openings and headlights. The headlights are new, employing upgraded technology to improve nighttime vision for drivers while retaining the signature yellow lights.

The tests are the first appearance of W Racing Team as the squad fielding the M Hybrid V8s, although the test days are being supported by RLL Racing, whose contract was not renewed after three seasons. “The time we have before the 24-hour race at the end of January,” said Andreas Roos, head of BMW M Motorsport, “will be used as effectively as possible to prepare both the cars with their updates and BMW M Team WRT for the first season highlight.”

The Aston Martin THOR Team made its first Daytona appearance with the Valkyrie, whose normally aspirated, screaming V12 will be heard by Rolex fans for the first time after making its IMSA debut at Sebring last year.

In the GT classes, Lamborghini’s new Temerario GT3 was introduced by Pfaff Motorsports in GTD Pro. Porsche introduced an evo version of its 911 GT3 R designated as a 992.2, which has an aerodynamic tweak in the form of a Gurney flap and other updates designed to make the cars more accommodating to drive, particularly for gentleman entrants. Teams can choose a new car or an update kit. Ferrari has an evo version of its 296 GT3 in the hands of Af Corse’s GTD team.

Various teams updated their driving lineups for the test days. Cadillac’s Action Express Racing added Connor Zilisch to its line-up for the test and the Rolex 24. Making his GTP debut, the rising NASCAR star co-drove to a class victory in the Rolex 24 at Daytona and Sebring 12-hour last year in LMP2. Other notable driver additions for the Rolex in GTP are IndyCar champion Alex Palou and A.J. Allmendinger (Meyer Shank Racing) and Colton Herta (Wayne Taylor Racing). The latter will be the test driver for Cadillac’s new F1 team in 2026 and compete in F2.

It was announced previously that Jack Aitken will do double duty this year for Cadillac in GTP and the WEC, replacing the retiring Jenson Button at Jota. Members of the Jota team were on hand in Daytona to help evaluate the V-Series.R’s new aerodynamics.

In the GT ranks, former F1 and IndyCar driver Romain Grosjean has been added to the Daytona lineup for the new Myers Riley Motorsports team, which is fielding a Mustang GT3.