Winter has arrived again, by the time you are reading this, or it very soon will, and it brings with it some of the biggest challenges to fuel economy. Once warmed up to their optimum working temperature, diesel and petrol engines actually operate with good efficiency in moderately cool conditions, as the cold intake air is dense and the combustion conditions are good. But it’s the lengthy warm-up period, when the combustion conditions are not so good, and the fuel consumed in heating up 200 kilograms or more of engine and transmission that knocks back cold weather fuel economy, often along with driving conditions and speeds that themselves will demand extra fuel.

How can we try and minimise these negatives? Short runs, when the car’s engine never gets warmed up even close to its best operating temperature, are to be totally avoided, if at all possible. Achieving that demands forward planning, and the best policy is to try and cluster together your car outings, with supermarket shopping done on the way back from another trip, and by avoiding any individual journeys to refuel, shop, visit friends, or make a trip to the waste recycling centre. So, it’s really in your hands! But anything much less than a 10-mile trip is not doing your car any good.

But there’s a lot of fuel wasted on the driveway, or at the roadside, as we prepare our car for any winter journey when there’s heavy frost, snow and ice about. Sometimes it may seem that there’s really no alternative to sitting in the car with the engine running, waiting for it to warm up enough to clear the windows, and give you enough visibility to drive safely. But perhaps we don’t think ahead often enough. How many of us leave our cars on the driveway, or outside somewhere else, just because the garage is too cluttered with who-knows-what to get your car in there? Garages are certainly gradually changing into storage areas rather than homes for vehicles, and it does us no favours with regard to motoring safety and fuel costs, to leave any car out in the open overnight.    

The garage situation generates some thoughts about future winter motoring though. Charging up electric cars is not something to be done on the driveway, and the ‘wireless’ inductive charging systems expected to become widespread in the coming years will logically be located in garages. Batteries also need to be kept as warm as possible to maximise their energy capacity and range, and heating up the cabins of electric cars in preparation for any journey needs to be done whilst they are on charge and in a garage, where less heat energy will be wasted. So maybe we’ll begin to see the motor car begin to return to its real home, in the garage, as we progressively transfer to electric power?

But that problem of frozen windows and accumulated snow and ice is a serious negative of winter motoring. It takes time to defrost a car, you can get very cold and cross whilst doing it, even with a proper scraper and de-icer spray. It often makes you late, and it does your engine no good at all, as it warms up so slowly when it is not using much power, just ticking over and wasting fuel. If you don’t have any of the kit that you need to help you clear your windows, you’ll surely struggle even more. Possible solutions? Full fabric car covers, from only around £50, from Halfords and Sealey are well rated, and windscreen-only covers that will keep frost and snow off are widely available; but easily fixed top covers for all the windows may be the best compromise for practicality that will soon get you rolling on the road, with your engine warming up properly as you drive. Compare the convenience and little time taken in just knocking off any loose snow, if necessary, and peeling off such a cover and stowing it in the boot, with the other long-winded and frozen hands alternatives!  Time to have a re-think maybe, if your car has to be left outside? Maybe it’s just time to get that garage cleared out?

Victor Harman