Hi George,
I have the 110bhp previous generation Avensis d4-d. I am just back from a trip to the Isle of Wight pulling our Avondale Dart 556-6 (mtplm 1300kg). I travelled from Stranraer in Scotland down the M6 to Birmingham and then M40/A34 to Southampton. The car pulled the van brilliantly. No problems with power at all. 60mph+ was easily achievable on the motorway and pulling out to overtake etc was fine. The kerb weight of my car is approx 1540kg (I have weighed it) and I found stability to be fine. However, I have fitted grayston rear spring assisters.
I reckon the 150bhp d-4d would be brillant in terms of power and acceleration. When it is time to change the car I will be looking for one.
Regards,
Andrew.