Home > Lifestyle > EnviroHealth > Green tips Updated 05 March 2013 Cool cars Which wins for fuel efficiency: the delicious chill of car aircon, or windows down with the breeze in your hair? Find out with these cool car tips. 0 Start A Health24 blog » Follow Health24 on Facebook » Test Are you envirohealth savvy? » Ask EnviroHealth Expert » Blood Lions: Bred for the Bullet movie trailer The amazing mountains on Pluto In terms of maximising fuel efficiency, you’d ideally never use the car air conditioner nor drive with the windows open – but we know that simply isn’t realistic in a hot climate.Still, if you want to save on petrol, keep in mind that car aircon reduces fuel efficiency by about 10%, so it’s always best to resist the temptation of that delicious chill as much as possible, and limit it to short blasts only. When you’re doing around-town driving at slower speeds, try to rely on rolling down the windows more for cooling. When you’re going faster on the highway though, at speeds above about 70-80 km/hr, having the windows open starts to significantly lower fuel efficiency because they increase wind resistance. At that point, for essential cooling aircon generally becomes a better bet. The aircon-vs-open windows debate is also complicated by other variables, such as the size and shape of your vehicle. A big boxy SUV is already poorly designed as regards aerodynamics, so it’s probably not going to make much difference if you open the windows. However with sedan cars, the difference in wind drag at higher speeds will likely be significant.Aim to combine use of aircon and open windows with your car fan and vents for cooling – these help to get a breeze moving without being a big fuel drain and air drag.More car-cooling tipsTo help reduce in-car temperatures and reliance on aircon, it also makes a big difference to park in the shade whenever possible, and use a windshield sunshade. Just as you would to save on cooling (and heating) your home, add or remove clothing layers accordingly: adjust your body temperature before you adjust your indoor, or in-car, environment. Plan trips so they don’t fall in the peak mid-day to mid-afternoon heat, and avoid rush-hour so you aren’t crawling along in a baking metal can. More fuel-saving tips: The walking busBe a road warrior Merge short trips Lighten your load Idle cars are poor performers Pump it upTame your inner roadhogGot a good green tip or event to share? Email me or post on the EnviroHealth Forum. If it's a planet-saver, we'll publish it.More EnviroHealth Tips Olivia Rose-Innes, EnviroHealth Editor More in Lifestyle Improved sunscreen More: EnviroHealthGreen tips advertisement Read Health24’s Comments Policy Comment on this story 0 comments Comments have been closed for this article. Logout Comment 0 characters remaining Share on Facebook Loading comments... From our sponsors Keep an eye on your vision Which skin products are better, ‘medical grade’ or ‘over-the-counter’? Win 1 of 6 R5000 cash prizes Win a R2 000 Skin Renewal voucher Live healthier Exercise benefits for seniors » Working out in the concrete jungle Even a little exercise may help prevent dementia Here’s an unexpected way to boost your memory: running Seniors who exercise recover more quickly from injury or illness When sedentary older adults got into an exercise routine, it curbed their risk of suffering a disabling injury or illness and helped them recover if anything did happen to them. No relief for MS » Drug shows promise against MS in mouse study Vitamin D may slow multiple sclerosis Obesity in girls tied to higher MS risk Exercise may not lower women's risk of MS A Harvard study showed no evidence to support the idea that exercise lowers the risk of multiple sclerosis.