Technical 2025 8 SPEED AUTO GEARBOX NOISE

[Normal4Norfolk]

Hi everyone, recentky taken delivery of a new Burstner motorhome in the UK with the 2025 ducato fitted with the 8 speed automatic gearbox and 140bhp engine. All seems ok so far EXCEPT.......when im travelling at around 45 / 50mph on the flat and the gear indicaor is showing D6 or D7 and i try to accelrate slightly - and by that i mean just tickling the accelrator i get a rumbling noise as if its saying your in the wrong gear - my diesel car with a manual box does this and i have to drop to a lower gear - ie it doesnt like 5th at 35mph......
The auto performs all ok at other times when accelerating harder - but as its a new van and im tight with money and want to achive better mpg i dont tend to kick it down or use hard accleration . Seems to do this more in ECO drive mode ....any ideas beore i go to my local fiat dealer ?

 

[lycopersicum]

As an aside, engines are most efficient when operating close to max torque / around half of the rated power. So while it pays off to reduce your cruise speed for obvious reasons, it's not necessarily a good idea to accelerate too gently.