Belgians are born Diesel drivers. They love the low price at the pump, and do not calculate (much) further. Our Flemish Automobile Association, the VAB, looked somewhat closer at the problem, and above all, made some practical consumption tests in collaboration with Toyota Belgium on the Zolder circuit. Their findings were somewhat surprising, to say the least, and certainly interesting enough to publish them here on our site…

Hans Knol ten Bensel

Modern petrol engines…

Indeed, the writing is on the wall: with the latest generation of (frugal) petrol engines, one has to think twice when choosing the right engine for today’s economic driving. In practical driving situations on secondary roads with their frequently changing speed limits, VAB test drivers found out that petrol engines consumed on average 10 % more than the factory figures, but more surprisingly, the consumption of Diesel engined cars was on average some 20 % higher than the factory data! Especially the so-called “eco-friendly” cars did not reach their attractive consumption figures…   

Petrol engined cars can often prove to be more economical than their Diesel engined counterparts. We drove the Toyota IQ in both engine versions at the Abbaye de Nizelles where the VAB and Toyota presented their surprising findings and test results...

The Belgian government rewards low CO2 emissions with premiums, and Diesel engined cars are the winners here… but only on paper. In daily driving situations, these cars would not win any of the government premiums due to their higher actual fuel consumptions(!)

… change the trend.

As if this were not enough, it should also be pointed out that the modern particle filtered Diesel engines need longer trips and distances to continue functioning reliably over the years. Their filters need higher temperatures to be effective, and these higher temperatures are only reached after 20 or 30 miles of motorway driving. The typical Diesel driver should absolve at least once a week a distance of some 30 or 40 miles at motorway speeds. If these conditions are not met, additional maintenance costs on the EGR valve and particle filter have also to be reckoned with.

VAB's Maarten Matienko presented the test results...

The “ideal” user profiles…

If one drives less than 15.000 kilometers per annum and mostly short (city) trips, then a petrol engine car is the obvious choice.

If one drives longer distances (as said, at least once a week some 30 miles at motorway speeds) and more than 20.000 kilometers per annum, the Diesel engine can be taken into consideration.

Toyota Belgium Public Relations Manager Koen Dekoning explains the merits of the >Toyota Optimal Drive concept to the audience...

Having said this, the price of Diesel fuel will also rise in Belgium. Europe will force the hand of the Belgian government in the coming years, as it will have to harmonise the tax level on Diesel with its neighbors.

And the environment…

As if this were not enough, Diesel engines are not good for your health, due to their higher emission levels of CH, NoX and minute particles. Only in 2015 will Diesel engines which will reach the Euro 6 Norm, and will they be as “clean” as modern petrol engines. Especially the higher PM and NoX levels are harmful for men and animals, and in our densely populated areas, this makes you (also) think twice…

Toyota test results…  

We already mentioned that Toyota Belgium participated in the test. Results proved that the Toyota iQ 1.0 VVT-I, which also benefits from the 15 % Belgian GVT premium, has a kilometer cost of only 0.35 cts when driven 10.000 km per annum, and 0.23 cts for an annual mileage of 20.000 km. This is lower than the iQ Diesel version, the 1.4 D-4D, which has a cost of 40 and 24 cents respectively. The differences are even more significant when the car is bigger: the petrol engined Avensis 1.6 Valvematic has a cost of 64 cts and 39 cts respectively, the Diesel version, the 2.0 D-4D, has a higher cost of 69,6 cts and 40,7 cts.

In 2020, the Hybrid Synergy Drive Concept on the Prius will be introduced throughout the model range, starting next year with the Auris...  

… and technology.

The modern petrol engines have of course come a long way. The Toyota Optimal Drive concept uses the Valvematic technology already explained elsewhere on this website, and last but not least do we mention here that Toyota has also further improved their Hybrid Synergy Drive concept on the latest version of the Prius, which we will drive soon. Total power of the system has increased by 22 %, and economy by a further 9 %. The CO2 and NOx levels are also lower than their “normal” Diesel or petrol engined counterparts, and it is not surprising that Toyota plans to introduce a Hybrid Synergy Drive version of all their models in 2020. The first step is already the introduction of a full hybrid version of the Auris next year…

Hans Knol ten Bensel

Toyota and VAB tested Diesel and petrol engined cars on the Zolder circuit and simulated driving conditions on Belgian secondary roads...