Here at TireReviews we often get asked what modifications are made to OE marked homologated tires, such as * for BMW, N for Porsche, MO for Mercedes and AO for Audi.

While the homologation process can take up to three years and involve numerous tests and changes, usually we have to give the very general answer of "stuff" as the data isn't made publically available. Thanks to Pirelli, we can now offer a simplified insight as to what changes major vehicle manufacturers have requested for the new Pirelli P Zero during the OE homologation approval process.

The new P Zero is available in three version, the P Zero (Luxury Saloon) which is only available as an OE marked tire, the P Zero (Sports Car) which is both OE approved and in the aftermarket channels, and the P Zero Corsa, which is OE approved for super cars. Full information on the new P Zero can be found in our launch report.

P Zero Luxury Saloon

The new P Zero (Luxury Saloon) is aimed at premium family cars, such as the Audi A6, BMW 5 Series and Mercedes E Class. As the chart below shows, the new P Zero (Luxury Saloon) has improved on the outgoing tire in almost every area, with big gains made in aquaplaning, rolling resistance, comfort, nose and wear, while still improving dry and wet handling.

Even with all these improvements, the OE manufacturers demand further changes to the tire before approving the tire for OE fitment. Below are some of the major manufacturers' changes to the P Zero Luxury Saloon version of the tire.

Audi

Audi requested improvements in rolling resistance, noise and mileage.

BMW

BMW, known to be a more dynamic drive than Audi, asked for improvements in dry handling, wet handling and a further reduction in tire weight to reduce unsprung mass and improve wheel control.

Mercedes

Mercedes have chosen safety, economy and comfort improvements for their version of the P Zero Luxury Saloon tire.

P Zero Sports Car

The P Zero (Sports Car) is aimed at performance vehicles such as Mercedes C63 AMG, BMW M3 and Porsche 911. The Sports Car version of the tire improves on the outgoing P Zero with a slightly different balance, as it offers smaller improvements in comfort, mileage and wear when compared to the P Zero (Luxury Saloon) version of the tire, but has bigger gains in laptime, dry grip, wet grip and braking.

AMG

AMG have further tuned this tire to improve the dry handling, driving consistency and lateral aquaplaning

///M Division

Were as BMWs ///M Performance Division have focused on laptime, weight, and straight aquaplaning performance.

Porsche

The unique usability and balance of the 911 has demanded improvements in dry handling, braking and rolling resistance.

P Zero Corsa

The final new tire in the range is the P Zero Corsa, which is aimed firmly at super car marques such as Ferrari, Lamborghini and McLaren. When compared to the original P Zero, it pushes the game even further in laptime, dry handling, wet handling and braking, but the OE manufacturers still have modification requests.

Ferrari

Ferrari being Ferrari, have demanded even more improvements in laptime, dry handling and consistency when driving hard.

Lamborghini

Lamborghini are slightly less concerned with ultimate lap time of the tire, but have improved the wet handling and rolling resistance.

McLaren

McLaren, like Ferrari asked for dry handling and laptime improvements, but instead of consistency, they improved the noise levels for their version of the P Zero Corsa.