Ford Focus: Smaller engine, lower economy?

  • Do smaller engines guarantee lower fuel bills?
  • An unlikely comparison allows us to find out
  • 1.6-litre Ford takes on 2.0-litre Peugeot 508

At Parkers we’re in the position where we tend to have a variety of different vehicles available to test. This means that the opportunity for interesting, although sometimes completely irrelevant, compare-and-contrast sessions arises on a regular basis.

Last week Peugeot’s new saloon, the 508, came in for a few days. It had a 2.0-litre diesel engine and it was refined, comfortable and competent.

Evidently this isn’t direct competition for the Focus, as the 508’s aimed at taking on the Mondeo. Covering a few hundred miles in it, however, revealed something quite interesting. Bear with me on this one.

The 508’s 2.0-litre diesel engine churns out 140bhp and 320Nm of pulling power. That allows it to propel from 0-62mph in 9.5 seconds. The eco-targeted Ford, however, packs a diminutive 1.6-litre diesel that generates 113bhp and 270Nm. That’s 27bhp and 50Nm less than the bigger Peugeot unit.

Despite the difference, the 1.6-litre engine is still capable of accelerating the Focus from 0-62mph in a respectable 10.9 seconds. That’s a relatively insignificant, in the real world at least, 1.4 seconds slower to 62mph than the Peugeot. Both are more than fast enough for daily use but the Peugeot’s added punch and low-down pulling power makes it the more relaxing, and flexible, car to drive.

You’re probably thinking “Of course it’s faster, but it’ll be using more fuel”. To some extent, you’re not wrong. Peugeot claim an average economy of 58mpg, whereas the Ford’s stated to be capable of just over 67mpg.

The reality is that the manufacturer’s figures are assessed under very carefully monitored and designed conditions that can differ wildly from the type of driving you do. That means that, in the majority of cases, you’ll never actually achieve what the manufacturer claims.

Driving both of these cars back-to-back demonstrated that point. The Focus, on my daily commute, averages around 48mpg. I have to work the 1.6-litre diesel quite hard occasionally, to overtake, and it seems that motorway cruising takes its toll on the economy.

The Peugeot, with its more powerful diesel, doesn't have to labour as much to maintain its speed. As a result, it returned an indicated average of 52.2mpg on my commute, in the same conditions. Even if you assume that the indicated figure is a few miles out, it still used a similar amount of fuel to my Focus. Thanks to the added power and torque, you can also overtake without having to drop a gear and floor the throttle. That saves more fuel.

Previously, many people's logic would dictate that if they were looking for the most economical car, they'd pick the smallest engine with the best quoted economy.

The reality is, however, that bigger – and more powerful – engines may actually prove more economical, depending on your usage. I get the distinct feeling that to get the best out of a smaller engine, with a high claimed average economy, requires diligent and slow driving. That can obviously lengthen your commute and make your drive stressful, as you try to avoid slowing other traffic. 

So, if you know that you can restrain yourself and drive slowly, you'd probably get the best out of the smaller engine. If you just want to get in and drive, however, it would probably be easier to get better economy from a more potent engine.

Obviously there are exceptions to this rule, and gearing also plays a part.

Nevertheless; if you're considering two engines with different outputs, try both. You might just be surprised.

Current mileage: 10,515 miles

Average mpg: 47.3mpg

More powerful 508 returned an indicated 52.2mpg with ease.