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Gran Cherokee: LPG vs/diesel 6-1

With LPG kit Tartarini

A ecological heart for the Italo-American of German origin

Born during World War II, the Jeep has become an off-road icon thanks to its qualities in this field. This success did not prevent it changing ownership several times, recently went from Chrysler to Daimler and Fiat: the fourth generation Grand Cherokee is an American model developed by German engineers, starting from the platform of the Class M Mercedes and revised by Italian technicians. The result is a luxury car we tested in an unusual variant: 3.6 V6 petrol Limited, not available in Italy, with the LPG Tartarini equipment.

Restyled in 2011, the design is characterized by the stylistic standards of the brand, such as the seven-slot grille, trapezoidal wheel arches and stretches tense. The streamlined shape is obtained thanks to the high waistline, the shape of the Bi-Xenon headlights, oversized wheels (265/50 R20) and aerodynamic improvements that have lowered the Cd from 0.40 to 0.37: it makes a slight impressive body (482 cm long, 194 wide and 178 high). Plenty of room to accommodate a basketball quintet with bags. Despite the spare wheel occupies part of the boot of 782 liters (1554 folding the seats) to make room for toroidal 69 litter LPG tank (55.2 effective) under the cargo floor with convenient removable compartments.

The driver's seat provides excellent comfort: large electric adjustment of seat and steering wheel, good materials and rational layout of the controls. The high seat makes it easy to view outside with the help of large external mirrors and screen colour 6.5” touch screen that into reverse shows the images of the posterior camera. In addition to infotainment, such as a radio with CD player and MP3 player and navigation system, also accessible via the steering wheel controls. The instrument panel is easy to be read, two main circular units with a central display with on-board computer data and the indicator of the selected gear from the five-speed automatic transmission with overdrive. Near the lever there is the switch / indicator of the LPG level. A pedal set the parking brake in motion.

The power button and it immediately detects the excellent soundproofing interior. The set-up is smooth and efficient, as well as road handling is excellent, thanks to low profile tires, multi-link independent suspension in the rear, to electronic devices. And to the permanent drive with differential lock control system and BTCS (Brake Traction Control System). To make it easier to drive also devices as Hill Start Assist and Hill Descent Control: the first facilitates hill starts keeping the brakes operated for a few seconds after you release the pedal and the second, which is useful in off-road, allow you to face heavy descents at a controlled speed without pressing pedal. The steering wheel is precise, but a little hard and requires some effort when manoeuvring.

The Grand Cherokee 6-cylinder 3.6-liter Pentastar V has dual overhead camshafts, aluminium block and variable valve timing for 286 hp at 6,350 rev / min and a torque of 347 Nm at 4,300 rpm. Acceleration from 0 to 100 km / h in 9.1 sec. and 206 km/h top speed. But it needs a very aggressive drive: at low revs the Jeep is lazy because of the large volume (2.4 tons), high wind resistance, friction of 4x4 transmission. The more revs rise the more consumption, already high, rise to 11.4 l/100 km (with gasoline at 1.6 euro / litre); that means more than € 0.18 per kilometre for fuel.

6 Cylinder Sequential Top Kit Evo by Tartarini makes the Cherokee more sustainable. The 257 hp power means a 10% decline that affects the top speed (197 km / h) without affecting acceleration. Consumption rise to 15.4 l/100 km, but without compromising the savings provided by lower cost of LPG. With gas at 0.72 euro / litre, the cost lowers by 40% to 0.11 euro, repaying the 1,800 euro for transformation in just 25,000 km.

Even autonomy gains: 800 km thanks to 93 liters of petrol plus 350 km on LPG. More positive effects on pollutant emissions, Euro 5 already contained with Euro 5 homologation and reduced by the chemical properties of LPG, while talking about the greenhouse, the carbon dioxide drops by 20% from 265 to 217 grams / km.

The version tested costs € 46,600 in Germany. In Italy the only fitting Overland, is on sale at 56,470 euro: 10,000 euro more for sophisticated technologies, such as the Quadra-Lift air suspension and Select-Terrain traction control. The first, in addition to greater comfort, adjusts the height from the ground in five different ways from the Park Mode (ride height of 16.5 cm) to the Off Road 2 (27 cm). The second consists of five driving programs (Auto, Sports, Snow, Rock and Sand / Mud) acting on 12 different parameters (throttle, transmission, transfer case, electronic traction and stability, etc...) for better traction on the different types of the roads. Many serial devices: ventilated front seats, leather upholstery, leather steering wheel / wood wheel heating, electric sunroof and tailgate.

The diesel version, 3.0 CRD Overland loses on almost all fronts. It costs 60,500 euro (2,230 euro more than the V6 converted) 0.13 Euro / km (0.02 more than the LPG), is less powerful (241 hp) and fast (202 km / h), but more agile (8, 2 "for the 0-100 km / h). On the environment, the diesel engine just loses the challenge against climate change (218 g / km of CO2 against 217 of the GPL) and in a clearly way the war to pollutants, especially particulate emissions. Final score: LPG 6, diesel 1.

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