Former Williams man Patrick Head says Formula 1 engines are "far too expensive" for what they are.
This season, the price of engines shot through the roof as the sport switched from 2.4-litre V8 engines to 1.6-litre turbocharged V6s.
And in a time when the sport is trying to curb rising costs, Head reckons the price of the engines has become too much.
He told the BBC: "I think the engines are fascinating pieces of kit, but I think they are far too expensive for what they are supposed to be doing.
"You could produce 800 BHP for €2m ($2.7m) a team each year. I think the teams are having to pay about 10 times that amount. It's a very expensive way of powering Formula One cars."
As of this season Williams are powered by Mercedes engines with the swap having heralded a revival for the Grove team.
Last year Williams scored just five points the entire season, this year they already have 52 points from six races.
"It's very good to see," Head said. "I think Pat Symonds and the other people who have come in, and the two drivers are doing a great job.
"I'm very pleased to see Williams, or at least a few of the people in Williams, albeit they know they need to do better, with a bit of a smile on their face, whereas going into a Williams garage last year was no pleasure for anybody."