Very High Fuel Usage After Start

[feanor]

Another new owner here, IS300h Mercury Grey

I am still getting used to it in general, and exploring all the various aspects unique to this car.

But one thing worried me, has anyone else noticed very high fuel usage first thing in the morning.

Im assuming it is the engine warming up, but it throws any economy saving out the window.

While viewing litres per 100km, the usage goes off the scale (which maxes at 30), no matter how lightly the pedal is pressed.

I quickly see the average being polluted by these figures, this morning right up to 11 litres per 100km, (after economical driving yesterday), it is disheartening to witness.

This seems excessive to me, and the engine is not revving very high

[ColinBarber]

The same as any other car, the engine runs rich when cold and idles fast to come up to temp as soon as possible. It is more noticeable with an economical car because it very quickly pulls down your average mpg.

[feanor]

Cheers,

That what my deduction also, the only reason I asked was that the engine was not revving up, but the fuel display went up to the max (30ltrs p/100km).

Even at idle, it seemed strange that the fuel could be used at such levels without engine revving, as during driving under normal conditions that would require a lot more revs to acheive.

Like you say probably a non-issue. However I just wanted to confirm this was the experience of other users, as with the level of computer control involved, I thought it might be a malfunction on mine.

Thanks

[Martin F]

As above, your engine will be running very rich after a cold start to try and bring the temps up, think about an old carb engine where you used to have a choke to restrict the amount of air entering the carb but still the same amount (or more) fuel. Same thing still happens on a modern engine and it will be more noticeable at the moment as we start to head into winter.

[Steve_L]

I can add my experience to this. After 3 months, there is still lots to learn about driving the hybrid, including the early morning thirst described by James. Last few weeks of cold mornings have been particularly noticeable with rear screen and front demist running.

Impact on overall figures depends on how far you have to drive. My normal commute is only 3 miles so average drops to around 38 (similarly to the 200d I replaced). However, if I travel to a different location, over 10 miles away, on a (reasonably) flat route, average will increase by around 20%. If I take an alternative uphill route, that is a different story - worst outcome is down to 36.

At the end of the day, the car has a 2.5 lt petrol engine which will be thirsty when pushed.

Great car though - and good colour choice James.

[Steve44]

Got to say that the IS300h warms up incredibly fast imo, compared to previous and other cars I've had.