Since getting the AUII XR6 HP, I haven't had the chance to have a really good long distance fang and see how the fuel economy was - until last weekend. I left Penrith with a full tank of Optimax and 3 other passengers, and as I usually expect, had a DTE of about 650. Naturally, with heaps of inner city hooning, this is about 200-250k's out of whack. My previous best from the car was 523k's with about 20 DTE to go, having done roughly 300k's of freeway (Central Coast and back and some M4).
At about 160k's down the Hume, my DTE was reading 636. Assuming the DTE is pretty accurate, that's an 800km tank, or 8.5l for every 100ks at that point in time.
I didn't refill again until the trip back. I'd done a reasonable amount of solid hooning about in Canberra (hard not to when your mate has a VR SS
), so by the time I stopped I had 540k's and 140 DTE, roughly 10l every 100. When I took off again, the DTE read 750. However, but the time I reached the Penrith/Cambelltown exit, my distance travelled + DTE was 850k's, or 8l per 100k's. Again, that will balance out when I return to city driving, but if the DTE is accurate and my maths haven't failed me, then 8-8.5l per 100k's isn't bad going.
Be interesting to see how it goes during the October trip to Melbourne.