Honda is continuing to improve its 2017 engine despite the fact that, according to the latest specialist media reports, the Japanese manufacturer and McLaren are now on the cusp of a split.
However, Honda chief Yusuke Hasegawa told the Japanese source Sportiva that the marque made a clear step forward at Spa.
"We assume that the improvement was one 10th, but in fact it may have been more," he said.
"It is difficult to see because of the characteristics of Spa, but if we would have run it in Hungary, the result would have been different."
Hasegawa said that the new specification seen in Belgium improved the torque of the engine at low speed.
"Although Spa is not a place where there are many low-speed corners, the 11th place in qualifying shows the effect of 'specification 3.5'," he insisted.
McLaren's Stoffel Vandoorne finished the Belgian Grand Prix in 14th place, while Fernando Alonso retired citing an "engine problem".
