Tales of the travels, trials and triumphs as we explore Australia in a converted bus

Motorhome Tour - Fuel Usage

We are often asked how much fuel it takes to move the bus. We have kept very detailed fuel consumption data from the very first visit to the diesel pump way back in 2003. Despite this wealth of data, the answer is not as simple as you would expect. We have had three very different configurations during this time and each configuration has very different fuel economy stats. Presented below are the configurations and the data for each. Note - these are long term averages and should provide a very good idea of the fuel economy for each setup. When talking about fuel economy we never refer to just one or two fills - the margin for error is just too great for the information to be meaningful. The more data include the more the averaging process removes errors introduced by :

Head or tail winds
Road condition
Hills
Increased load (perhaps caused by us needing to travel with full water tanks)

Configuration 1 - Bedford 466 engine and Moke

The Bedford Engine

When we purchased the bus, it was powered by the original Bedford 466 diesel engine (non-turbo) and we had the Mini Moke stored under the bed.

Total distance traveled with this configuration	29778 km
Total fuel used	8301 liters
Average fuel consumption	3.66 km/l 27.3 l/100km

This old Bedford engine was slow and loud - but it never let us down and we never abused it. It was a good engine but technology has moved on quite a lot from the 1940's when it was designed.

Configuration 2 - Isuzu Engine and Moke

The Isuzu Engine

In 2005 we removed the Bedford engine and replaced it with a smaller, lighter, more powerful Isuzu 6BD1-T turbocharged diesel Engine and a 6 speed manual transmission. This changed not only our cursing speed but also our fuel economy. We were very pleased with the results from this transplant.

Total distance traveled with this configuration	78447 km
Total fuel used	18180 liters
Average fuel consumption	4.35 km/l 22.9 l/100km

This represents an improvement of 18% over the old engine. During this configuration we saved over $1,500 on fuel (when compared with the amount we would have used with the old engine).

Configuration 3 - Isuzu Engine and A-Framing a Suzuki Vitara

The Vitara

In 2011 we purchased a 1993 Suzuki Vitara and put a 3.75m boat on its roof. This vehicle is A-Framed behind the motorhome and the Moke was placed in storage. Along with the boat came some additional equipment, added fuel, the outboard and safety gear, all of which is stored where the Moke used to be located. So while in theory we removed about 700kg from the bus when we took the Moke out, in reality we put much of this weight back with boat and other gear.

As this is the current configuration, we have very little data. These figures should therefore be considered less accurate that the long-term data presented in the two configuration above.

Total distance traveled with this configuration	2767 km
Total fuel used	710 liters
Average fuel consumption	3.86 km/l 25.9 l/100km

This is a drop of 12% when compared to the configuration with the Moke inside the motorhome. We find this difficult to account for as we did not expect the additional rolling resistance/load to increase our fuel consumption by this much. We travel a little slower now that we tow the car behind and hills seem quite a bit more of an effort (perhaps because we are travelling slower??).