1. MYTH: ACCELERATION’S SHORT DUE TO THE SMALL REV RANGE…?
FC says: True, but only if you drive it like a petrol. Diesel engines generally have lower rev limits than their petrol counterparts, but this isn’t a problem if you’re in a higher gear. In fact, the extra diesel torque can often make it just as quick, if not quicker. Plenty of modern diesel engines have awesome performance figures!
2. MYTH: YOU CAN’T GET BIG POWER OUT OF A DIESEL…?
FC says: OK getting big bhp isn’t as easy as it is with a petrol engine. But 100bhp per litre on standard diesels, and 200bhp per litre on tuned engines, is becoming common. When it comes to torque per litre, diesels have petrols beaten hands down, with diesels producing far more torque than power – often nearly double. In the US many have already been pushed to 1,500bhp!
3. MYTH: ALL DIESELS ARE SMOKEY…?
FC says: It’s true to some extent, but, if tuned right, it should only happen a little on full throttle. This is because the ideal air/fuel ratio for maximum power on a diesel engine is around the same as a petrol lump. But unfortunately at this level the exhaust will be pouring out thick black smoke! Because of this, diesels are always set to run lean as a trade-off between maximum power and how much smoke you’re happy to have at full power. Don’t worry too much, you can still see well over 100bhp per litre (and around 200 lb/ft per litre) without much smoke, if tuned properly.
4. MYTH: ALL DIESELS SOUND AWFUL…?
FC says: Due to the incredibly high compression ratios and combustion pressures in a diesel you’ll never have a smooth purring engine like you can have with petrol. That said, modern diesel engines are far quieter than the noisy old beasts that most people think of. With lower compression ratios, enabled by high-boosting turbochargers, and huge improvements in fuel injection systems, giving better fuel delivery and timing, they often only make any noticeable diesel clatter when they’re idling. Even then most are very quiet.
5. MYTH: PERFORMANCE DIESELS DON’T EXIST…?
FC says: That’s so wrong it almost hurts. With plenty of production diesels managing a sub six-second 0-60 it’s obviously not the case. In motorsport, pretty much every Le Mans-winning car since 2006 has been a diesel. They also hold both the lap and top speed records there, so it’s nothing to do with better fuel economy and fewer pit stops.
6. MYTH: YOU LOSE ALL THE FUEL ECONOMY IF YOU UP THE POWER…?
FC says: OK, it’s a given; the more power you have, the more fuel you use. But just because you have a big power doesn’t mean you have to spend your entire life at full throttle! If the car’s fuelling is set up, it should be almost as economical as standard when cruising. Granted, you won’t be able to go flat-out everywhere and still do 50mpg but we’d much rather have a car that cruises at 60mpg and can still out-accelerate Evos. Power when it matters!