DIN

Fuel Saving Trends

While there’s already been a huge amount of talk around the price of diesel, we’re not going to apologise for continuing to raise the subject, whether it’s looking at alternative fuels, like we did last month, or looking at reducing fuel consumption, this month.

When it comes to fuel economy a large percentage of the potential improvement is down to the driver or operator and neither repairers nor body-builders can do anything about that aspect.

Fortunately, how efficiently the equipment does what it needs to do, is influenced hugely by you. That extends from work you can do on existing vehicles and equipment to input you can have on the specification, configuration and design of future purchases.

Years ago, in another life, we supplied parts for a large fleet of buses. The chief mechanic was always annoyed that he and his team spent so much time and money fixing a particular type of bus that was just not up to the job.

They used more fuel than the older, but more powerful, versions of the same bus, on the same runs; because the drivers had to work them harder on the hilly sections and then drive them faster on the flat to make up lost time.

As a result they also required more maintenance and so the small initial saving made by purchasing a smaller-engined bus and the expected fuel savings never worked out as planned by the ‘pen-pushers’. Instead, they were simply the ‘wrong tool for the job’.

I guess he complained loud enough because the company never made that mistake again but he was stuck repairing them, the drivers were stuck driving them and the company was stuck paying for them for several years.

We priced supplying larger replacement engines as each one came up for an engine rebuild, on behalf of the chief mechanic, and that probably would have paid off quite quickly but the purchasing officer wasn’t about to admit he’d made a mistake and so it never happened.

The point is that qualified technicians are often better educated, better qualified and better equipped to be involved in these sorts of equipment spec’ing and buying decisions than owners and operators/drivers or accountants. Let’s hope someone’s listening.

So, what are the things that can be done to improve the fuel efficiency of the equipment you’re already working on?

Obviously, having equipment serviced properly is the first thing and some lubricants work better than others at reducing fuel use – notably synthetics. Some additives also work really well but then others don’t.

We’re not advocating experimentation here but someone has probably already done that part for you, so ask around to find out what works and what doesn’t, if you want to explore those possibilities.

At open road speeds cross-lug, rear tyres are claimed to use 2 to 3 percent more fuel and low tyre pressures use even more fuel than that. Improperly aligned axles can use similar amounts of extra fuel.

For trucks and buses idle reduction systems, cruise control and fuel computers are becoming popular driver economy aids that technicians need to be familiar with and may even need to test by doing back to back comparisons of the aftermarket systems available, to find the best gear.

Aerodynamics is becoming a big selling feature for new trucks and buses but it’s just as important across the whole fleet. The manufacturers are doing a great job showing what works and what doesn’t, so a lot of that technology can be retro-fitted to existing vehicles.

It’s not just big roof mounted ‘pod’ style air deflectors either. Basically, the body shapes are a lot smoother and more streamlined, with almost no external fittings or ‘air traps’ anymore. Gone are the extra marker lights, stone-deflectors, air horns and other accessories that were once common fare. Mirrors are smaller and aerodynamically shaped and even aerodynamically mounted too. Air-cleaners are mounted out of the way, often in the engine bay and exhaust stacks are disappearing.

Then there are the aero side pods and chassis fairings to smooth airflow over and around the wheels, axles, tanks, battery boxes and other components.

Trailer gaps are coming down to the ‘magic’ 38-inches and aero aids like roof fairings are now appearing on the trailing edges of the truck bodies to maximise trailer ‘slip-streaming’.

It’s a huge growth industry and it obviously works too. In the case of a poorly performing older style rig, a full aerodynamic ‘clean up’ can make a bigger difference than all the other improvements put together, if you believe the stories.

At 90 kph, in a modern aerodynamic ‘long nose’ rig, more than half the fuel burnt is just to overcome air resistance and at 100 kph it’s at least 6 percent worse. Remember, that’s with a new aero truck, just imagine what an old-style rig with lots of accessories hanging off it is like.

New trucks are now being launched with their aerodynamic and fuel saving ability as the main attraction. For example International has announced its new heavy-duty ProStar tractor has more than 4 percent better fuel economy "than the nearest competitor." This is thanks to the ProStar demonstrating 9% less aerodynamic drag, International said.

They then go on to recommend a whole series of other aero add-ons to supplement the existing fuel consumption reductions.

Now that diesel has doubled in price and is still going up, fuel saving ideas that weren’t so cost effective before suddenly make a whole lot more sense now. It’s big news right throughout the diesel industry – bigger than emissions reductions, which will probably also use more fuel - so we’ve all got to do our part to cut fuel costs or the industry will just go backwards.