Valtteri Bottas will start Sunday's Belgian Grand Prix from third, after clocking a 1:43.094 on his final flier to leapfrog Kimi Raikkonen in the second Ferrari.
"First of all, congratulations to Lewis for his 68 poles, that's a mega achievement," said the Finn.
"Unfortunately, I didn't have the pace to fight for the pole today. I'm not sure about the reasons; I'm slightly confused as to why I haven't been able to get closer. We will need to look for a few more answers in the data.
"The balance in the car felt good, but I was lacking grip, so I was particularly struggling in the high-speed corners of sector two. I felt a lot more comfortable in the car with high fuel, so that's good for tomorrow.
"Driving the 2017 car around Spa is mega - it's so quick, I've never experienced anything like it. We are both starting in the top three, so as a team we will still try to achieve our target and that is a 1-2."