While driving two days ago I noticed that my fuel consumption at idle is higher than normal, ie 0.62-0.64 LPH instead of the usual 0.52-0.54 LPH. Everything was the same as usual: the only power draw were the LED DRLs and the cabin fan at lowest setting. A/C was off (broken).
On the way back I noticed it again and kept an eye on the SGII. Idle consumption was at 0.62-0.64 even though the engine had been up to operating temperature (78°-80°C) for more than 10km/15min. Only after about 20-25 minutes did it finally drop to its normal ~0.52 LPH, and I noticed then that the coolant temp was up to 88°C, but it stayed at 0.52 even when the engine cooled back down.
Any ideas what could be going on?
One thing that crossed my mind was increased internal friction, but my oil level is OK. In fact, it's been two years since I changed it and I haven't had to add a single drop. (Yeah, I know I should change the oil more often, but I just plain forgot. You can yell at me now. I'll have it replaced with fresh 5W30 before winter.) Could it be the oil?
Oh, and can I use a thinner oil than the 5W30 (Total Quartz Ineo) that PSA strongly recommends? I found a 0W30 (Total Quartz 9000 Energy), but I wonder if it will protect the fussy engine/turbo as well, especially with the higher temps I see with the winter grille block on? 0W30 is also about 40% more expensive
