Petrol vs. Diesel - Round Three
- 2008 Hyundai i30 SR 2.0 litre petrol manual - $26,490 (RRP)
- 2008 Hyundai i30 SX 1.6 litre diesel manual - $21,490 (RRP)
- Metallic Paint $300; ESP, TCS, Side & Curtain Airbags $1,790 (SX - standard on SR)
- by Matt Brogan
Our last Petrol vs. Diesel Comparo featuring the sassy Skoda Octavia drew the scoreboard at one-all. Now the pressure is on and the final round's contender has a tough job to sway the argument one way or the other.
The final comparo for this season features Hyundai's brilliant i30 hatch, and though we've been impressed with the i30 before, the results of this little experiment blew us away.
First up the sporty looking Vivid Blue SR went in to bat for its petrol brethren offering a 2.0 litre four cylinder petrol CVVT (Constantly Variable Valve Timing) engine not uncommon in spec to that found in the majority of small hatches.
On paper the synopsis is quite typical of an engine this size and the claimed economy figures do seem relative to the category, but just how these figures relate to real world driving can often be misleading.
Hyundai i30 SR (petrol) in Vivid Blue
How a car delivers its available power can be all together another thing to what seems true on the spec sheets. Body weight, throttle response, gear ratios, valve timing, electronic aids and chassis set up can all impact the way in which power is delivered, and the personality of this delivery can vary greatly in cars with near identical specifications.
Whilst 105kW @ 6,000rpm is a respectable output for an engine this size, the revs build in a far too linear fashion meaning the peak power delivery is never really felt and you’ll eventually find yourself on the rev limiter without having really achieved very much, almost as if the valve timing or cam lift needs revision.
It's fine around town and it leaves a lot of its competitors looking like they’ve had one too many cheeseburgers, but out on the open road, especially through hills and windy bits, you just never really seem to be able to use all that the engine could offer, no thanks to a rather short torque curve.
The 186Nm on offer comes in soon enough for good pull from the lights, but fades off sharply after 4,600rpm creating a gap before the power peaks. In turn this leaves an exposed and weak high end which is further hurt by a gearbox ratioed to deliver fuel economy and little else.
First and second gear are quite tall and pull you from a standstill well, even with four people on board I had no trouble, but the all important pulling power expected from third gear just isn't there and the loss of momentum at this crucial juncture is irretrievable.
The gap from second to third gear ratio simply does not match the overlap in torque/power delivery meaning a huge loss of power delivery at speed which can make highway overtaking very lethargic.
Final fuel economy figures came in a little over our expectations. ADR tests claim 7.2 litres / 100km combined average which was by our reckoning a little optimistic. Our results, 8.6.
Now don't get us wrong, the petrol i30 is a good little car, and in comparison to similar hatches it's brilliant, but it could be so much better but for a few minor alterations in gearbox ratio and/or CVVT settings. If you're not after a spirited drive and are happy to go with the flow, this little beasty may just suit your needs.
However if you'd prefer a little more pep, and a lot more economy, then get a load of this. Forget everything you'd thought of small capacity diesels, the i30 CRDi is revolutionary in its ability and almost unbelievable in terms of power delivery and economy gains.
Hyundai i30 SX CRDi in Shine Red
It's a rather quiet and smooth diesel, and most people won't believe it is in fact diesel until you show them. Using modern common rail technology and a sweet little turbo charger, the 1.6 litre twin cam engine is surprisingly quick to rev, incredibly strong in terms of torque and amazingly efficient.
Presenting 85kW @ 4,000 revs and a very tidy 255Nm from just 1,900 rpm, the little oiler builds power very quickly and holds its torque over a nice thick band to offer incredible pulling power in all manner of driving circumstances. City gridlock, country cruising, freeway fastlanes, and windy alpine roads, it seems no challenge is to great for the i30 diesel's stamina.
The gearbox is well matched to the power on offer and provides a flexible spread of gear ratios for any situation. Although the (gearbox) linkage feel could have been a tad smoother, it is nonetheless very easy to shuffle through from cog to cog with a nicely weighted clutch helping the CRDi feel that it will pull in just about any gear all day long.
Now for the best bit, the fuel economy. After my week with the car I managed an average of 4.7 litres / 100kms, which funnily enough is bang on that quoted by ADR tests (how often does that happen). On the open road lowering this figure is an easy task whilst around town trying to persuade the car to drink more than 6 litres was nigh on impossible.
Clearly then, the third round of our little comparo is awarded to the diesel vehicle. Not only has it proved a strong performer with its athletic performance but the economy figures just cannot be argued with.
If you're the market for a new car, and the model you're interested in offers a diesel option, then by all means drive both. You'll be stunned at what a modern diesel can offer and no doubt further pleased with economy gains achieved.
Scoreboard - Diesel 2 : Petrol 1