For those of you travelling a lot, especially those who are full time on the road or doing “The Lap”, consider travelling at 10-20km/h under the speed limit.
Now I know there will be resistance to this, and that’s fine, everyone is entitled to an opinion, but contrary to many opinions, the posted speeds are the limit, not the goal. And yes of course I had different opinions when I was younger, but we all have to grow up eventually.
On my recent trip over to Adelaide and through the Riverland area of SA, I tested this (it’s not the first time I’ve done this though). On day one I was on a tight schedule, and ended up doing about 1000km. So I was travelling at the speed limit to fit all my stops into the day as planned. My fuel usage ended up being 9.4L/100km which is pretty good all things considered.
However the following 3 days were no longer on a schedule, so I was able to take it easy. I travelled at about 80km/h in the 100 zones, and about 90km/h in the 110 zones. At the end of the trip it dropped my average fuel usage down to 8.8L/100km, which means the slower speed actually used about 8.3L/100km, which is almost 15% less fuel. These are approximate figures, and will vary with different vehicles. My vehicle is a 2011 Renault Master 2.3L Turbo Diesel.
But it’s not only a fuel saving… Slower speeds also reduce tyre wear, I’ve seen suggestions of half the wear at 80km/h v’s 100km/h, I think this is a bit of a stretch, but tyres lasting 25-50% longer is a good thing in any language. There’s also wear and tear on the engine, it’s not working anywhere near as hard. This is partly due to wind resistance, but also because you’re no longer pushing it hard to pass others, you’re just sitting at a constant speed and letting others have the stress of passing you. The chances of a caravan swaying out of control are also much lower. In the event of an emergency, the distance before you stop (in a family car) at 80km/h is about 70m, but at 110km/h it’s closer to 115m, a lot can happen in 45m! Put a caravan behind you and this can be double.
And lastly it’s way more relaxing not having to worry about passing other vehicles, having a bit more time to view the scenery, and having more time to consider stopping for something you want to get out and look at, rather than doing a U-turn. By the end of a full driving day at the speed limit, I’m physically and mentally very tired. But sitting well below the limit I’m feeling much better.
For those that are going to complain about slower vehicles holding up traffic, don’t bother. If you can’t safely pass a vehicle doing 20km/h less than the speed limit, you shouldn’t be behind the wheel. Passing a slower vehicle like this is much easier, faster and safer than trying to pass one going the speed limit, and you don’t have to break the speed limit to pass them… Win Win. I had a couple of times when I felt the right thing to do was to pull over when it was safe and let a few vehicle pass me, and in doing that I got the wave from several people and the indicator flick from trucks showing appreciation.
You may think it’ll take you longer to get where you need to get to, and that’s true, but that time isn’t normally proportional to the speed you travel at due to stopping and starting, breaks, fuel stops and corners. Slowing down 20% may only cause 5% extra time before you arrive at the destination.
Accidental fines for going a bit over the speed limit… also a thing of the past.
As always, driving to the conditions and traffic is something we should all do. There are times when driving close to the speed limit or at the same speed as others, is the most appropriate and safest thing to do. And there are times when slowing down even more is necessary.
Safe travels everyone!
