With these mods the BRM V12 matched a DFV on power, but revved higher, at 11,500rpm. “Which meant we used more fuel,” says Tony. “We’d start with 10 more gallons than them – 48 in total. But it was great for qualifying.”
That slightly melted shape is down to the two bag tanks, one each side, outside the chassis, to lower the centre of gravity and minimise weight shift with fuel usage. It was as much an aesthetic decision as anything else, says Southgate. “My previous car was the ’69 Indy Eagle which had flat-sided tanks because no-one in the States would do compound curves in metal, and it wasn’t very glamorous. In Britain we were knee-deep in men who could bash out curved panels.
But if BRM now had a serious contender, it also had serious opposition. Ferrari’s 312B and Matra’s MS120 both matched it for rev-happy V12s, Lotus was fielding the advanced 72, and everyone else had that field-sweeping wonder, Cosworth’s V8. Still, with Rodriguez and Oliver aboard, and sometimes a third car for George Eaton, its qualifying positions improved race by race, until round four – Spa. From the third row, the Mexican pushed through to take the lead on lap five – and took it to the flag. The drought seemed to be over, but it was a one-off. Often rapid in qualifying, sometimes challenging for points, the 153 repeatedly broke its engine, gearbox or axle, as Oliver recalls. “In the quest to reduce friction they used needle-roller bearings in the hubs, which raised a stress point at the axle neck. So the front wheel kept falling off.” Which caused Oliver to collide with Jacky Ickx at Jarama; both cars burned out.
“I guess we built around five of them,” says Southgate, which makes this one, Chassis 05, about the last. It can’t claim any wins, but it is extremely original. Its debut was the Dutch GP in June 1970, where Pedro Rodriguez placed tenth, but it followed with three DNFs before Pedro scored fourth in Austria. Oliver then took it over, but suffered three more failures before Mexico brought a struggling seventh. With the improved P160 quickly on stream the 153s were retired, and in typical Bourne style, stored. 05 went direct to the Donington Grand Prix Collection from the BRM sale in 1981 and has since been restored by BRM specialists Hall & Hall. Sitting in Donington’s huge museum, gleaming in red, white and gold, it’s a reminder of a flash of hope during BRM’s darker days.