I’ll be taking a few more trips to Newcastle over the new few months. My father is recovering well and we’re helping him with a few jobs around the house. So there’s a few chances to baseline the fuel consumption under fairly arduous conditions. Parameters:
- Tyres at 45psi
- Lower grill fully blocked
- Full tank of Caltex 91 RON (ethanol free)
- Temperature 10 – 20°c
The run from Canberra to Northern Sydney was at night from just after 21:00. Not much traffic and sticking to the limit, even up hills. The mythical Super Highway Mode still eludes me. Rather than cut through Bankstown, Rhodes and Ryde, which is nice but hilly, I took the M7 and M2. I chose that route as I assumed that the roadwork I had encountered on the M2 a few weeks previously would either be finishing or would at the very least be no worse. Boy was I wrong. The entire stretch of the M2 I used was a 40km/h zone (I remembered it as a 60km/h zone!) adding about 30 minutes to an already long journey. Arriving at midnight is not too bad. Arriving after 00:30 seems silly.
Early start to Newcastle on the F3 carrying a niece and nephew as cargo. The F3 is a bit busy and a bit hilly for cruise control. Pleasant drive interrupted by a wanker driving a black Volvo XC90 who overtook in the left hand lane (contravening Rule 141 and common sense) and then cut me off received a good toot from my horn and some choice words from the grown ups. Language warning belatedly given to the young children in the back seats. Obligatory toilet stop at Ourimbah for the youngsters didn’t delay things too much, I thought.
After a highly productive day we returned in 3 cars: Sister and brother-in-law ahead, us in the middle and Dad behind. We managed to maintain this order for the entire journey and for some parts had no other vehicles in between. I thought that I should keep an eye on Dad so I kept a reasonable distance ahead of him. This meant charging up the many steep hills on the F3 at nearly full power. Not great for fuel consumption. Here’s the funny thing; our formation flying was a complete fluke. Dad had left before us but had discovered a new dead end. The two other cars left together, but the superior torque of the Citroën turbo diesel allowed it to overtake on Carnley Avenue. Dad appeared in my rear vision mirror and stayed there for most of the journey. Arrived in Northern Sydney within 2 minutes of each other.
Roundabout way of saying that we travelled 854.6km (about 10km past the DTE=0km mark) using 38.22l of petrol at 4.47l/100km. Considering the flogging I gave the car, it was about 0.5l/100km better than I would have expected a few months ago. The return journey to Canberra was 284.0km at 4.6l/100km (4.2 on the HSI) at an average speed of 92km/h.
So, did the grill blocking help? It’s possible that it helped the aerodynamics at high speed. Just wait until the next tank fill; I’m expecting low 4’s. That’s almost certainly down to the rising temperatures. And the grill block.