Volvo’s new flagship XC60 3.0T has been equipped with a technologically advanced turbocharged six-cylinder engine that is optimised for a very sporty driving experience and the highest possible performance, but with the lowest possible fuel consumption and exhaust emission levels.
Coupled with the new Volvo XC60’s effective and permanent All-Wheel Drive system, the 3.0T petrol turbo engine is used in an optimal manner by transferring the maximum amount of power very effectively onto the road surface.
The 3.0T engine, offered next to the D5 turbodiesel as power sources in the new Volvo XC60, was a finalist for the 2008 Ward’s 10 Best Engine awards and it is based on the compact 3.2-litre in-line aluminium engine that has been part of the Volvo engine range since March 2006.
The turbo version of the normally aspirated 3,2-litre engine has a displacement of 3 litres, producing 210 kW and no less than 400 Nm of torque which is on tap from just 1 500 rpm and remains available all the way up the revolution range, resulting in rapid acceleration (0-100 km/h in 7,5 seconds) and smooth driveability.
Twin-scroll technology is a main feature of this powerful and efficient engine. The application of this technology delivers an impressive torque curve that actually represents a flat line on 400 Nm from where it starts at very low engine revolutions of only 1 500 rpm. It permits the use of a more compact and uncomplicated turbocharger and provides extremely swift response, fully on a par with that from twin turbochargers.
The technical solution to create a compact 6-cylinder engine that could be mounted transversely in accordance with Volvo’s philosophy, was retained in the turbocharged 3.0T – with gear housing also located at the rear of the engine and all auxiliaries located above the gearbox.
The camshafts in the 3.0T have a hollow construction which results in low weight and the intake camshaft is equipped with CVVT (Continuous Variable Valve Timing). Both inlet and outlet valves of the 3.0T have a smaller diameter than the non-turbo 6-cylinder. The smaller diameter for the outlet valves contributes to increased gas speed and accordingly increased speed for the exhaust turbine of the turbocharger.
To withstand the higher exhaust temperatures that turbo operation produces, the outlet valves have been manufactured in a temperature resistant material that contains 70% nickel. Both inlet and outlet valves are controlled via fixed tappets.
The exhaust manifold is produced in high-alloy cast steel to withstand the high loading and temperature of the turbocharged combustion process. In the event of extremely high loading the manifold could reach a temperature of 900ºC.
Twin Scroll turbocharger technology
Twin Scroll technology means that the outlet or exhaust manifold consists of two separate ducts that run into the turbine section of the turbocharger. Exhaust gases are moved from the cylinders in accordance with the ignition sequence, i.e. when cylinder 1 is evacuated of exhaust gases, it is followed by cylinder 5, then cylinder 3-6-2-4.
Thus the turbine rotor is fed alternately by exhaust gases from the two different ducts in the manifold and the turbine housing.
The Twin Scroll technology has been selected so that it produces equally high output but requires less space than an equivalent system with two separate turbochargers. By means of the gases that flow from the separate exhaust ports not affecting each other in a negative way, the pulse energy from the exhaust gases is used very efficiently, and a high torque is achieved at low engine revolutions.
Full torque, 400Nm, is achieved at 1500 rpm.
This results in very good performance when starting from stationary and good acceleration characteristics.
Cooling the turbocharger
During operation the turbocharger, which contains bearings that run at very high rotation, is cooled by the circulating engine oil. At the same time there is a weak throughflow of coolant. In the very important cooling phase after the engine and its systems have been switched off, the turbocharger is cooled by self-circulating coolant.
In this position the coolant in the turbocharger could reach a temperature of 125ºC. The coolant then starts to boil, and the gas bubbles that form rise to the expansion tank. The rising gas bubbles are replaced in the turbocharger by colder coolant. This self-circulating process is known as thermosyphon and could continue for 5 to 10 minutes.
Double cooling fans are used for the 3.0T engine in hot markets such as South Africa in order to achieve maximum possible cooling capacity.
Energy-efficient turbodiesel from the second D5 generation
At its introduction in South Africa the new Volvo XC60 will also be available with the D5 turbodiesel, producing 136 kW and a massive 400 Nm of torque all the way across a particularly wide range of engine revolutions.
The D5 engine features an electronically controlled turbocharger, advanced multipoint injection technology and a very powerful engine management system. Four-valve technology with twin overhead camshafts contributes to swift response and good high-speed properties in the D5.
A maintenance-free particle filter that traps about 95% of soot particles is fitted as standard in both engines, making them very environmentally suitable.
XC60 Engine range
Petrol Configuration Power (kW) Torque (Nm)
3.0T AWD 6 cyl. in line, turbo 210 400
Diesel
D5 AWD 5 cyl. in line, turbo 136 400
Six-speed Geartronic
The engines in the new Volvo XC60 are mated to a six-speed automatic Geartronic gearbox with the choice of manual gear changing.
The transmission has been dimensioned to handle the very high power output of the 3.0T and the D5 turbodiesel. Sixth gear is a pure overdrive ratio and offers relaxed, economical cruising.
Geartronic makes it possible to change gears manually should the driver prefer a sportier driving style or if he or she wants to hold on to a specific gear.
