• -
  • irishtimes.com - Posted: June 8, 2012 @ 12:16 pm

    Crunching the numbers

    Neil Briscoe

    It’s not often that, in this job, you get to drive two different versions of the same car, back to back. Generally, schedules are just too hectic to spend such an amount of time on one model of car. You drive maybe one version, and then don’t see it again until the facelift in a couple of years time. It wasn’t like this in the old days, I can tell you. Why, back then there was time to drive every version of any new car, have a leisurely lunch and still have change for the bus fare home… Ahem.

    But recently, and quite by chance, I found myself behind the wheel of two versions of the Skoda Superb at more or less the same time. One was the expected diesel version, a 1.6 TDI 105bhp Greenline, and the other was an unusual choice, a 1.4 TSI petrol. Deciding between the two, I assumed, would be the work of a moment. Ireland is a diesel-hungry car market right now, my daily drive involves about 200km of motorway and I’m a cheapskate. The diesel had it in the bag.

    Hmmm. Perhaps not. The 1.4 TSI engine, long familiar from a whole generation of VW products, should have struggled with the Superb’s weight (1,477kg for the 1.4, 1,524 for the 1.6 TDI) given that it’s giving away 50Nm of torque to the diesel. It’s the old story; a large car with low torque means that you spend ages in the higher reaches of the rev range, getting the damned thing up to speed and that knackers your fuel consumption.

    Not so though. The 1.4 TSI revved cleanly, crisply and it hauled the bulky Superb around with barely a sweat broken, something that my observed fuel economy (Skoda claims 5.9-litres per 100km, I was getting mid-sixes) confirmed was not just a subjective feeling.

    This just didn’t compute though. How on Earth was a supposedly unwanted petrol making damned near as good a fist of powering a large family car as an equally-supposedly superior diesel?

    Perhaps hopping into the diesel would clear everything up for me. Nope, it didn’t. Yes the extra hit of torque at lower speeds was welcome, but in all other respects, both engines felt absolutely neck-and-neck, with the petrol edging it for aural refinement, the diesel in terms of low-down-lug (but not, surprisingly, opening out a big lead in terms of fuel consumption).

    All of which got me thinking. We’re all rushing to buy diesels right now because that’s what the taxman, in not so many words, says we should be doing and we all assume that filling up from the black pump is saving us money. But is it, really? It was time to break out the calculator and crunch some serious numbers. Pardon me if my arithmetic is off in any way; I flunked Leaving Cert accounting…

    Right, the two cars are very similar in terms of purchase price with the 1.4 TSI Ambition clocking in at €26,195 and the 1.6 TDI Greenline costing €27,670. Advantage petrol, but only just.

    Tax, of course, gives the advantage back to the diesel but again, only just. with €65 between taxing one or the other for a year; €160 for the Band A diesel, €225 for the Band B petrol.

    Next came insurance, and assuming you’re a 36-year old accountant living in County Dublin with the car parked on the driveway, you can expect to pay essentially the same for both cars; €466 fully comp for the petrol €468 for the diesel.

    I notionally financed both cars through Skoda Finance, with a 10% deposit and a three-year term. Now, obviously, that’s not necessarily representative of reality and real customers will have trade ins and be rolling over other finance deals, but I’m assuming that you’re coming in cold, off the street and paying cash. Unrealistic, but at least it assures a level playing field for both cars. That done, the monthly repayments are €735 for the 1.4 TSI and €738 for the diesel.

    Now then, fuel consumption and this is where the diesel pulls out a significant advantage. Taking the prices currently on the board at my local Texaco (€1.54 for a litre of diesel, €1.64 for petrol) and assuming you’re doing 16,000km a year at the officially quoted fuel consumption figure (again, unrealistic but fair to both cars) the petrol’s 5.9-litres per 100km figure will cost you €1,458 a year in fuel-ups, while the diesel’s 4.4l/100km will save you the guts of €500.

    Depreciation is a tricky thing to measure, especially given the uncertainty in the Irish car market at the moment, but we can make a couple of assumptions. A quick trawl through the classifieds shows that year-old Superb Greenline diesels shed about €4,000 from list price to list price. There simply aren’t enough 1.4 TSI petrols on the ground yet, so I’ve taken a leap-in-the-dark guess and assumed that it will lose €5,000, on the basis that diesel is king and the lower tax band will better prop up the value of the diesel model.

    So, taking all those figures together, you come up with a total first year cost of €18,678 for the 1.4 TSI petrol and €17,289 for the diesel. A €1,400 saving over the course of a year looks like a convincing win for the diesel, but remember, if my casual depreciation assumption is wrong, then that advantage is all but wiped out.

    Have we learned anything from this? Probably not, except that petrol is not quite the busted flush we all assumed it was, and that 20-minutes doing some 6th class maths could really make a difference to your car buying decisions.

    Pencils down, everyone, and don’t forget to show your work…

Search Motors