Hi,
We have a 150 bhp diesel Aventura automatic which seems a bit underpowered. Considered one of the upgrade chips, but noticed that all of the automatics are 150 bhp whereas the manuals are 170 bhp.
Does anyone know if the auto box can take the extra power?
Ray

Hi

Looking at getting this too - is yours a new model 2007- ?

Thanks
J

Hi Razorman,

I was just about to post exactly the same question so was wondering if you ever managed to get a definitive answer?

Cheers

I have a Ventura on a 57 plate and am thinking of fitting a Tunit unit has any one any experience with this unit on a 150bhp automatic , this unit will take the out put upto 170 and like the other contributors I to am concerned that the auto box has a 150 as standard and the manual a 170bhp ?

Could be that the gearbox couldn't take the extra power, but it could also be something as simple as they want to keep the emmisions down so lower the bhp? Haven't got a clue but just a thought?

Spoken to Tunit technical guy this morning and he says that he has had feed back from many xtrail owners with auto boxes and they have not had any problems, only good things to say about performance and fuel economy. Tunit give a warrenty for 12 months on the engine and drive train so they are pretty confident that no problems will occur. I have tried talking direct to Nissan and got the usual "not recommended to modify from original spec however local Nissan dealer tech says that he can't see any problems ? and Tunit say that they have supplied over 80% of units for auto transission cars without problems.

Nissan fitted the 150bhp engine because the box can't take 170+. Therefore, I'd be very cautious about pumping up the power to much more than that, but suspect there is a bit of leeway, so 170 is likely to be reasonably safe.

Mechanically the 150hp and 170 hp engines are the same(turbos, injectors etc) Even the ecu is the same. If you order a new ECU, it will be blank. Nissan flashes new soft on it, depends from VIN code or sticker on the ecu -150hp or 173hp, but ordering codes are same.

I have now covered 20,000 miles with the Tunit unit fitted and found reasonable results, fuel consumption 26 urban very short journeys, 35 to 42 on combined journeys and 42 to 46 on motorways all solo with tunit set to number 3.
All the above with light presuure on acclerator and getting the auto box into highest gear possible by using the manual selection.
Towing I get an average of 28mpg and I always tow in 4 wheel drive, I set the Tunit unit to 7 or 8 for towing which seems to give me good power.

My exhaust pipe is squeeeky clean, no carbon or soot at any time , I have also a fitted a K&N air filter.

So far , touch wood, no adverse effects on auto gear box except sometimes overruns when turning into a side road and box changes down to lower position, this may have nothing to with the tunit unit just a quirk with the Nissan auto box ?

Out of interest I had to tow a fully laden long wheel base transit out of a mudy field backwards last year, not a problem with box in lock, towed like a dream. Tyres fitted Pirelli STR's

I just read 2007 issued local car magazine the other day where there was then-new T31 test drive article.
Journalist asked Nissan why there is not 170hp automatic available. Answer was that a auto box does not have cooler, fluid may get too hot when car is pushed hard in urban cycle.
Keeping that in mind i would say auto box itself can handle extra power from ECU re-flash/chip. Adding cooler to auto box isn't rocket scinece aswell.