The Argument between Diesel and Petrol answered.

Many articles have been written regarding the efficiency versus price contest of diesel and petrol engines.

When you add up the advantages and disadvantages of both motors there normally is no clear winner, the Alfa 159 1.9JTDm now clearly defines the winner.

Diesel cars are normally between $2,000 to $5,000 more expensive than their petrol brothers – The Alfa 1.9JTDm is the same price as the 2.2JTS Selespeed.
Fuel rating guides state diesel to be around 2L/100kms more fuel efficient. In real world driving, the average driver can attain closer to the stated consumption figures in the diesel than the petrol.
Diesel motors don’t rev out like a petrol motor. The high torque figures at low revs in the diesel are more suited to the natural characteristics of automatic transmissions, moving the car along at lower revs.
The extra price for diesel fuel minimizes the advantage over petrol. I could easily achieve 800kms on a tank of fuel, almost twice what you would expect from the 2.2 petrol in real life driving.

The Drive

I took a brand new Alfa 159 1.9JTDm 6 speed automatic from the dealership for a Sunday drive down to Kangaroo Valley in the NSW South Coast via Mittagong and Bowral.
Through the mountains into Berry for lunch then back again. Combined with a lot of driving through mountain roads and country towns there was some time spent on Sydney city roads too. The car had only 25 Kms on the clock when I left and brought it back with exactly 450Kms, so the car had not been “run in” at all, therefore I expected a very average fuel consumption figure. The Fuel Consumption Guide states 7.1 litres/100Kms combined and the trip computer told me I had used 7.5 litres/100Kms, not bad for the first drive of a car and I definitely was not trying for a low fuel consumption record!

I have to admit I was not a fan of diesels having driven trucks for 10 years in a former vocation, so the Alfa had a lot of winning over to do for me to prefer it to a petrol motor. Also I had never driven any Alfa 159 for this long, so I was excited to be doing this trip.

Some things in the car were unusual, but the further I drove I began to understand that those idiosyncrasies justified themselves completely. For example, in manual mode at 80kmph, 4th gear was the highest gear you could select. At 100kmph you can choose 5th gear but not 6th until 110kmph. At first I thought this was stupid and inefficient and stuck the gear selector back into D for the rest of the day, but the more I drove, the more I realized that this gearing and engine breaking helped me keep to speed limits and cruise control limits, making for a far more comfortable cruise than my regular 5 speed automatic drive car.

The tiller is a great size and the leather quality and thickness was very comfortable. The accuracy of the steering and minute 2.4 turns lock to lock is fantastic on those tight mountain turns, always allowing you to keep total control via only slight movements on the steering wheel. The quality and thickness of the leather extends to the seats as well, along with the now famous Alfa logo on the front head restraint. The suspension is sporty but compliant, to be expected knowing Alfa’s 100 year history and sporting prowess. Alfa’s racing glories include having Enzo Ferrari as a team driver then manager before starting his own company. More recently, Fiat own Alfa, Ferrari and Masserati, the latter working very closely with Alfa on research and development. So if you are looking for a soft lounge chair on wheels, look elsewhere. Alfa is sporty and doesn’t pretend to be a luxury barge.

The huge torque figures also showed how comfortable and relaxed it was to drive up the steep and winding mountain roads. I wasn’t trying but I left a Suzuki Swift Sport way behind, he probably wasn’t trying either.

So, considering the purchase price is not a premium over the petrol equivalent, the real life fuel consumption is far superior, the 6 speed automatic has advantages over the Selespeed box from the 2.2 and the drivability is better, the contest is very one sided, in favour of the diesel.

Come in and see for yourself. We have 4 diesel 159s on special at present so take one home as a present to yourself!