Fresh guidelines for F1 engine tweaks

At present suppliers Mercedes, Ferrari, Renault and Honda are allowed to make changes to improve the power unit on the grounds of safety and cost, along with reliability, without the need to use the permitted tokens for upgrades.

Now the FIA is demanding a clear explanation from all the teams as to why a change on reliability grounds would be required.

The technical directive issued by the FIA, and seen by AUTOSPORT, reads: "All requests for changes to the homologated power unit for the purpose of improving reliability should be made to the FIA in writing with copies to the FIA F1 Engine distribution group.

"All such requests, with supporting data where necessary, should be made eight days before the modified power unit is first used at an event and must include:

"Complete explanation of the failure (clear photographic evidence but also when and where the failure(s) occurred; part number references for old and new parts; exhaustive drawings of any new/modified components; test and investigation results supporting the request where applicable; any relevant supporting information from external suppliers."