If we're turning away from diesel, where does Strong think we have to look? Plug-in hybrids, he answers, but not those mated to diesel engines (gas-electrics are his choice). According to his information, a hybrid diesel will produce more pollutants due to the lower exhaust temperature and he wonders if it makes sense economically. Diesel fuel is actually more expensive than gasoline in the UK: £1.25 per liter compared to £1.10, which he translates into £350 more per year when driving 20,000 miles per year.
Sparkless engines aren't totally done for, Strong says, and expressed hope for HCCI (DiesOtto) engines. This technology has a very narrow powerband, which compromises reliability - but Strong says that Ford might be working on solving that issue.