During the Belgian Grand Prix weekend, it emerged that the Mercedes AMG Formula One team’s fourth-spec power unit, introduced at Spa, would possess a clear cut advantage over its Ferrari counterpart for the rest of the season.
The regulations regarding oil burning have now been locked in place at 0.9 litres per 100km, whereas the limit for power units introduced in Belgium was slightly higher, at 1.2 litres per 100km. Mercedes took advantage of this and introduced their update at the right time, meaning for the rest of the season, they will have a 0.3 litre oil burn per 100km advantage over Ferrari, who, along with every other team on the grid (including Mercedes customer teams), will only be allowed to burn 0.9 litres until the end of the season.
— Valmar Viisel (@paddocknews) July 24, 2017
So what are the possible advantages of burning oil at a slightly higher rate? Firstly, oil within the Power Unit can act as a coolant through the system, allowing the unit to be sustained at a more optimal level for a longer period. If you’re allowed 1.2L per 100km over 0.9L, you have 25% more coolant, so can run the power unit at its maximum level for longer without fear of overheating and frying the system.
This possibly explains why Mercedes, in particular, can seemingly turn the car up a notch in Qualifying. In the race, “It’s Hammertime” could translate to “Now you can flick that switch that burns oil at the highest rate, meaning you can have full power for some time.”
— F1 Feeds (@f1feeds_) March 21, 2017
Back in pre-season testing, when oil burning was a big topic too, F1 techie Craig Scarborough wrote:
“As part of the new 1.6l hybrid power unit rules, fuel consumption was restricted to 100kg of race fuel and instantaneous fuel flow capped at 100kg\hr. If teams wanted more fuel to go into the engine in either the race or qualifying there is nothing that can be done. But, of course everyone wants more power and a means to do this is to burn more hydrocarbons. Petrol is one source of these, but so too is the oil circulating through the engine. If you can burn a little oil then you can gain some power, so the option is an attractive one, if difficult to achieve legally.
If an engine performance map also included the crankcase pressure as a parameter, then the solenoid can legally be tuned to alter the level of that can be burnt. Already F1 engine burns a lot of oil, some 3-5l may be used during a race, this consumption has gone up from about 3l under the old v8 rules, so clearly something might be going on and the technical directive has been issued to point out that oil usage will be monitored to cap any escalation. Is there any impact? one or more of the current F1 power units may well be burning oil for combustion performance. There is a small power boost for this in both qualifying and resulting fuel efficiency boost (burn more oil – less fuel) in the race.”
– Craig Scarborough
— Feral Motorsport (@FeralMotorsport) August 29, 2017
Any issue with Mercedes having a slight advantage in this area over the rest of the field should be taken up with the FIA technical directive rather than aimed at the team itself, who are only doing their jobs and showing innovation. It begs the question as to why Ferrari didn’t follow suit, and could have massive ramifications on the title fight this season, especially at the many circuits remaining in which claiming pole is a huge advantage.