Even though some people are quite knowledgeable in the motor vehicle area, hopefully there are only a few who actually think that American trucks still run on petrol. The truth is, that the technology there does not differ substantially from the European utility vehicles. There have even been company- and thus technology takeovers, eg., Mack by Volvo and Freightliner by Daimler.

As far as the optic is concerned, in the USA and Canada we speak of vehicles with a bonnet and very often with almost luxuriously equipped, large cabins. Since here, only the length of the trailer is regulated, and not, like it is in Europe, the complete vehicle. Nonetheless, an American truck is not substantially heavier. For example, a large portion of its bodywork is made from synthetics, this can be noticed sometimes by the enormous amount of shuddering when idling.

As far as the engines are concerned, there's hardly any difference at all. Almost exclusively six-cylinder in-line engines are used, a technical direction in which one of the last eccentrics, Daimler, will probably also soon swing. Current models already have a gearwheel drive for the horizontal overhead camshaft, which also drives the pump injector elements. Very new in some smaller engines is the 4-valve technology and Common Rail.

The total displacement in the big engines is still between 11 and16 liters and a little more than than 441 kW (600 HP) of performance. The turbocharger has a variable turbine geometry which is operated, nowadays, completely electrically. The exhaust gases do not yet comply with the Euro 5 or even the Euro 4 standard. As a rule, cooled exhaust gas recirculation, for the reduction of NOX, and a combined closed particle filter with oxidation catalyser are used. Occasional post-injection of diesel fuel into the exhaust manifold provides for the necessary regeneration.

Neither are there essential differences to be found as far as the clutch and gearbox are concerned. Whether 3 x 6 speeds, 3 x 5, or 2 x 2 x 4 are changed sequentially, makes no real difference in the construction of very modern trucks. However, some older ones can only be driven by double de-clutching. Although only the first rear axle is driven in the normal traction mode, there are often two. Only if the first one starts to slip, the mechanically controlled drive is transferred, through a short connecting shaft, onto the rear axle.

The changeover from steel springs to air suspension, as well as from the drum- to the disc brake happened in America and Europe similarly. The brakes are always operated by air pressure, ABS releases air in the event of wheel-locking. (EBS) electrically controlled brake has not really been introduced into America as yet.

Also the appearance of the tractor-trailer rigs can differ very much from those in Europe. Depending on the state, it's also possible to add an additional trailer onto a conventional tractor-trailer outfit. Alternatively, there are 3-4 rear axles in the semi-trailer and a second trailer is added. These combinations, which are foreign to us, are not tolerated in some federal states, which means that they must simply be avoided by detouring around them.

Sometimes there are even additional axles in the middle of the vehicles or the semi-trailers. When not in use, they are of course, raised. While cornering when loaded however, this axle is pulled very slowly, but certainly, straight across the asphalt.

Any questions about the safety standards authority? The safety inspection is half-yearly, the same as it is here. I could not find out whether the examiners must be suitably trained or not. Exhaust emission tests are not standardised yet and therefore, depend very much on the enthusiasm of the examiner. Sometimes the county (comparable to our administrative district) also stipulates the standard.

On the highways (interstates) there are, at regular intervals, weigh-bridges, when they are open all trucks must take a compulsory break. At this opportunity the police-officer can order additional checking in workshops in the surrounding area, and/or also even test the exhaust gases himself with a long measuring tube. The safety standards authority check-up for motor cars, vans and pickups is, by the way, once a year. 07/07