May 14 (Reuters) - A 'megaphone' exhaust tested by Formula One leaders Mercedes in Spain on Wednesday failed to make the quieter new cars sound any louder, race driver Nico Rosberg said on Wednesday.
"It wasn't a great solution," the German said in a video posted on Instagram after he had lapped Barcelona's Circuit de Catalunya with what looked like a shiny vuvuzela at the back of the car.
"It just didn't work. It didn't make it much louder. So we'll just have to look for another solution."
The season's dominant team, runaway winners of all five races so far, had agreed to try out the trumpet-like device to try and pump up the volume after complaints that the new V6 turbo hybrid cars were too quiet compared to the old V8 screamers.
The softer sound provided an immediate controversy when the season started in Australia in March with some race promoters, who met in Barcelona on Saturday, fearing ticket sales could fall off if fans were alienated by the lack of decibels.
Others in favour of the quieter new era argue that increasing the noise goes against the greener spirit of the regulation changes, which reduce wasted energy from the exhaust and brakes and harness it to improve fuel economy.
"It's an interesting moment in time for Formula One," Mercedes motorsport head Toto Wolff said last weekend. "Traditionally you would have said... that Formula One needs to be loud to be spectacular. Maybe now that's changing."
While the noise, or lack of it, was a talking point on Wednesday others got on with their regular business.
Red Bull had quadruple champion Sebastian Vettel in their car while Venezuelan Pastor Maldonado topped the fairly meaningless timesheets with Lotus.
Williams had Wolff's British wife Susie getting acquainted with their car before she becomes the first female driver since 1992 to feature in a grand prix weekend when she takes part in practice at Silverstone in July.
She was fifth fastest and did 55 laps.
Belgian reserve Stoffel Vandoorne had his first drive of a Formula One car and completed enough laps with McLaren to secure the superlicence he will need if a race seat comes his way.
The 22-year-old, currently competing in the GP2 support series, finished runner-up last year to current McLaren rookie Kevin Magnussen in Formula Renault 3.5 and is seen as a talent for the future.
Vandoorne did 136 laps - more than twice the distance of Sunday's Spanish Grand Prix - in a programme reserved for testing Pirelli's hard tyres. Other drivers used the medium or soft compounds.
"This has been a fantastic day for me: my first experience in a Formula One car, and a really great opportunity to get plenty of laps under my belt," said the Belgian. (Reporting by Alan Baldwin, editing by Toby Davis)