Volvo Upgrades Power, Lowers Fuel Consumption of 2.5L Flex-fuel Engine

14 May 2009

Volvo Cars has boosted the power of its five-cylinder, 2.5-liter Flexifuel engine by 30 hp and delivered an additional 40 N·m of torque. (Earlier post.) The 2.5FT now produces 231 hp (170 kW) and 340 N·m (251 lb-ft) of torque. At the same time, Volvo engineers have cut fuel consumption by between five and six percent depending on transmission.

Fuel consumption (EU, mixed driving cycle on gasoline) for the upgraded 2.5FT is 8.8 L/100 km (26.7 mpg US) (V70) and 8.6 L/100 km (27.4 mpg US) (S80) with manual transmission, and 9.7 L/100 km (24.2 mpg US) (V70) and 9.6 L/100 km (24.5 mpg US) (S80) with automatic transmission. This is an improvement of about 5% for the manual versions and almost 6% for cars with automatic transmission.

When running on E85, fuel consumption increases by about 30% since bioethanol contains less energy. The exact difference depends on factors such as driving style, ambient temperature and variations in fuel specification.

The increase in the 2.5FT engine’s torque and power output was made possible by adopting new software that raises the turbocharger's boost pressure.

Fuel economy has been improved by cutting engine revs in specific driving conditions. In cars with manual transmission, this takes place by fitting a longer gear set with an increased span between first and sixth gear. In this way, fifth gear has the same ratio as the previous sixth gear, while sixth is now a pure overdrive ratio.

In the automatic version, the reduction in fuel consumption has been achieved with a new gearchanging program that changes up earlier at lower engine revs.

The upgraded 2.5FT engine will reach markets in Europe in the Volvo S80 and Volvo V70 in June 2009. Both variants are available with a choice of manual or automatic transmission.

Volvo Cars has one of broadest ranges of Flexifuel models; five models—the Volvo C30, S40, V50, V70 and S80—can be specified with one or a choice of two E85 engines.

In addition to the turbocharged 2.5FT engine, both the Volvo V70 and the S80 have since the end of 2007 been available with a four-cylinder 2-liter Flexifuel variant (2.0F) producing 145 hp (107 kW) and offering 185 N·mof torque. Fuel consumption (EU, mixed driving cycle on gasoline) is 8.6 L/100 km (V70 2.0F) and 8.3 L/100 km (S80 2.0F).

The Flexifuel variants of the Volvo S40, V50 and C30 have a four-cylinder 1.8-liter engine (1.8F) that produces 125 hp (92 kW) and torque of 165 N·m. For these models, the fuel consumption (EU, mixed driving cycle on petrol) is 7.3 L/100 km (C30 1.8F) and 7.4 L/100 km (S40 1.8F and V50 1.8F).