A truck in numbers: gears, power, tyres, fuel tanks, engine life and speed

The documents makers publish put a long-haul tractor unit in Europe at 8 to 16 forward gears, 206 to 574 kW and 1,350 to 3,800 Nm, on 22.5-inch tyres from 295/60 to 315/80, with fuel tanks of 150 to 910 litres each. North American documents put a Class 8 tractor at 9 to 18 gears, 320 to 605 hp and 1,000 to 2,050 lb-ft, with tanks of 40 to 150 US gallons each. In the EU a speed limitation device holds goods vehicles of categories N2 and N3 to 90 km/h. On rated engine life, North American documents print a B10 figure of 1.0 to 1.2 million miles and a B50 figure of 1.2 million miles; in Europe, Iveco and FPT give up to 1.6 million km for the XCursor 13, and a 2012 Mercedes-Benz release a B10 value of 1.2 million km for the OM 470 and OM 471.

Status as at 5 November 2026. The EU, German and US legal texts cited were read on that day, apart from Directive 96/53/EC and 49 CFR 565.15, read in early October 2026. The makers’ figures come from the documents behind this site’s model pages, opened between September and early November 2026.

A long-haul truck at a glance

Weights and lengths are set out in how much a semi truck weighs and semi-truck dimensions. The name itself is covered in what a semi truck is.

How many gears

The gearbox families behind these counts are described in truck gearbox types. All counts are forward gears, as each maker prints them.

How much power and torque

European makers’ documents print kW and Nm, often with hp beside them; the North American truck makers’ documents read here print hp and lb-ft. How to read a truck’s power figures sets out what each unit means. The European rows below cover each record’s whole engine list, which can include gas engines and engines for rigid chassis; the North American rows name the engine. In the units of the other column, 605 hp is about 451 kW and 2,050 lb-ft about 2,779 Nm, by our arithmetic (605 × 0.7457 and 2,050 × 1.3558).

How big the tyres are

All the European sizes below carry the rim code 22.5. The first number is the nominal section width in millimetres; truck tyre markings explains the rest of the code.

No tyre maker’s data book was opened, so the weight of a single tyre is not verified for either market. Two official texts set limits that bear on what a tyre carries. Directive 96/53/EC allows 11.5 tonnes on a driving axle and 10 tonnes on a single non-driving axle in international traffic (Annex I, points 3.4 and 3.1). In the United States, 23 CFR 658.17(f) says that “States may not limit tire loads to less than 500 pounds per inch of tire or tread width, except that such limits may not be applied to tires on the steering axle”, and paragraph (c) sets 20,000 pounds on any one axle.

How much fuel the tanks hold

How much diesel weighs

Directive 98/70/EC on the quality of petrol and diesel fuels sets limits for fuel placed on the market. Annex II of the text adopted on 13 October 1998 gives density at 15 °C a maximum of 845 kg per cubic metre and no minimum. That is at most 0.845 kg per litre, or about 3.20 kg and 7.05 lb per US gallon of 3.785 litres, by our arithmetic. It is a ceiling, not the weight of any given fuel. Annex IV of the same text, required by Article 4 no later than 1 January 2005, prints no figure for density. The later consolidated text of the Directive was not opened, and neither was any US official text with a density figure. What a truck burns is covered in truck fuel consumption in official data.

How many wheels and axles

The first figure of a code such as 6x4 counts wheel positions and the second the driven ones, as axle configurations explains. DAF’s UK sheets list tractors as FT 4x2, FTS 6x2, FTT 6x4 and FTM 8x4. Volvo’s FH data sheets list tractors as 4x2, 6x2, 6x4 and 8x4, and add 8x2 and 10x4 for rigid chassis. In North America, Volvo draws the VNL and International lists the LT as 4x2, 6x2 and 6x4; the Peterbilt and Kenworth documents read print no list of wheel formulas for the diesel tractor, and Freightliner names single and tandem rear axles. HABAŞ prints the tyre count of its SteelPower 4x2 as “6 +1”. How the wheels of a five-axle combination add up to 18 is in what a semi truck is.

How far an engine is rated to last

The figures below are the rated engine lives found in the truck documents read. Mercedes-Benz’s release of 14 March 2012 says, in our translation, that its B10 value means at least 90% of the engines reach that distance without needing a general overhaul, and Peterbilt’s brochure of 2021 words its own as “Up to one million miles without a major overhaul”. None of these documents says how the figure is worked out or what B50 stands for.

Cummins’ own X15 bulletin 5410582 prints no rated life. It gives a warranty, which is a different number: base coverage “good for 2 years/250,000 miles (402,336 km)” and extended plans “for up to 7 years or up to 600,000 miles (965,606 km)”. Detroit’s Extended OPTIMUM page gives coverage options for DD13, DD15 and DD16 engines of 6 months to 3 years and 50,000 to 375,000 miles (80,500 to 603,750 km), and no rated life.

How fast it may go

A speed limitation device and a road speed limit are separate rules. Directive 92/6/EEC says in its recitals that it “does not affect Member States’ prerogatives as regards speed restriction provisions for traffic”. National limits across Europe are collected in truck and bus speed limits in Europe.