Neel Jani says LMP1 privateers are now faced with the “difficult” task of manually saving fuel per lap in order to not exceed the FIA’s energy limits for non-hybrid competitors.

The 2016 FIA World Endurance Champion crossed the line in third in last weekend’s season-opening Total Six Hours of Spa in the No. 1 Rebellion R13 Gibson, although was excluded post-race for excessive skid block wear.

While being one the quickest of the LMP1 non-hybrids, Jani and co-drivers Andre Lotterer and Bruno Senna were forced to be in fuel conservation mode all race long, oftentimes estimating the fuel numbers per lap.

It came as an eye-opening experience for the ex-Porsche LMP1 factory driver.

“Each pit stop we lose 10 or 15 seconds to the Toyota on the refuel,” Jani told Sportscar365. “Then we have less laps [stints], and we have to do a lot of fuel saving.

“It’s difficult for a team like us because we are under using fuel now, because we cannot over-use unless we get a penalty.

“There’s no software like we had at Porsche so we’re just guessing [by] ourselves, plus/minus. And that is a lot of time lost.”

LMP1 non-hybrids were permitted to utilize 47.1 kg of fuel per 17-lap stint at Spa, but without the computers and software utilized largely by the LMP1 factory teams only, Jani feels it puts privateers such as Rebellion at another “big-time” disadvantage.

“We’re allowed to use 2.66 [kg of fuel per lap] but we were using mostly on average 2.60 just to be safe, because we lifted ourselves… we had to guess by ourselves,” he said.

“So already we lost a lot of time on each lap… and that was for sure a big-time loss for us.”

The No. 1 Rebellion finished two laps behind the race-winning Toyota TS050 Hybrid, although Jani admitted that nearly 90 seconds of the deficit was lost for penalties and other gremlins.

It included a five-second stop-and-hold penalty in the second hour for exceeding the maximum amount of fuel per stint by 2.74 kg, as well as a stop with 1 hour and 50 minutes to go to replace the FIA’s mandatory data transmission antenna, which had stopped working.

While disappointed with the gap to the hybrids, Jani hasn’t laid the blame entirely on the EoT, admitting there are still “a lot of things” that have to be improved from the team’s side as well in its debut race with the ORECA-built prototype.

“We had to do quite a lot of fuel saving per lap but also we had quite a lot of issues,” he said.

“We were hoping to be only one lap down, to be honest. But on the other hand, we lost 1 minute 30 [seconds] with this other thing in the pits and we lost another 30 seconds in the first [safety car]. So that’s a lap.

“I don’t think it’s completely two laps, but clearly, the most difficult part for us is when we have to refuel because, for us, we don’t know where we are.

“We don’t have the software. We are always not going to be efficient with that.”