Trying to get some details on towing a caravan of around 2500kg with the Pajero (NW).
I will have to load it up and get it on a weigh bridge to make sure all legal requirements are sorted – Front axle, Rear axle, Towball, ATM , GCM). Early indication are it will be on the limit.
Its a 3.2D auto fitted with the MM4X4 Auto-mate PRO. I was skeptical that this was required before towing the van. But after the trip home I was straight up looking for something to supplement my control while towing. My initial concerns were AT temps, EGT, fuel usage and just general wear and tear on drive train while towing.
I got the ScanGauge III, and fitted a cheap EGT sensor and dial to give me enough telemetry to feel informed and in control. The EGT sensor is fitted just behind the turbo, so I will assume the temps is about 100-150 degrees Celsius lower than what I should be monitoring.
Firstly. The MM4X4 Auto-mate torque locker. It’s not perfect and for everyday driving, I turn it off. I like to think that the factory has tuned the car pretty well and having a vehicle largely unchanged for 10 years, I feel the general driving experience when not towing is quite well sorted with the Pajero.
Saying that, stick the caravan on the back and load up the car, the 3.2D feels like a nice big lazy unit that is letting the gearbox do more than its fair share of work. This is where the auto-mate lets me share that burden with the donk. It essentially becomes a semi-auto when you stick it into sports mode. I love this. I have always loved driving manual vehicles, so this is almost the best of both worlds. Watching the EGT, AT temps and instant fuel use, gives me the details I like to pick the right gear based on the driving situation.
I found on the freeway you generally toggle between 4th and 5th, occasionally dropping to 3rd. Anywhere between 1800-2000, depending how far the top of the incline is, you can choose to drop a cog. I’m not expert but what I thought would cause EGT to rise is not what I expected. The Pajero seems to be OK to pull just over 1850rpm, and will sit nicely around 2600rpm but happy to rev over 3000rpm if required (it doesn’t quite sound right having it sit that high in the rpm range, but it works). As a result, 5th was utilised on the freeway when sitting around 100km/h (in a 110km/h zone) but generally anything under 95km/h I’d knock it back to 4th.
I found I didn’t need the 5th gear lockout option from that auto-mate on the freeway. Any driving that is 90km/h, the 5th gear lockout is an awesome feature. Stick the car in “D” and the auto-mate works as I’d hoped it would. There are a few glitches here and there, however this was documented in the documentation provided. Overall, I am impressed that the MM4X4 auto-mate pro works as I hoped it would for towing.
Fuel efficiency from Brisbane to Boreen Point (Australia, about 160kms each way) was around 15L/100kms while towing. Previous tow was just under 17L/100kms on a shorter trip, so I’m not sure what the comparable saving is in fuel usage. But I think about 2L/100kms (+/- 0.5L/100kms) would be a ballpark. Planning a 20,000km trip around Oz at ~$2/L , that is a (very conservative) saving of about $800.
Auto Temp. There is a good video that the MM4X4 team has made demonstrating this (youtube here –> https://www.youtube.com/watch?v=toRtbOcJj0A, and check out their website https://www.mm4x4.com.au/). So I won’t go over that again. The AT temps hover between 85-90 degrees C most of the time on this trip.
EGT. The EGT on this vehicle was low (350 degrees C) most of the time. Up a long slight incline it might jump just over 400, and then up a long steeper incline (a little hard to describe exactly – thought there was a sign that said 12% and it was about 2kms long), stayed under 600 degrees C. Remember, this is the temp after the turbo. For a short period, this is not an issue as the EGT quickly drops down to 350 after the top of the hill was reached. From what little I have gathered, if you get high EGTs (say 800 degrees + before the turbo) for continual extended periods of time, that heat soaks into the engine block and other engine components. At some point, you will see your temp gauge move on your engine. At this point it’s probably to late and you are going to blow something up. There is only so much heat/energy that your engine can absorb before something gives. That is why it is nice to know what is going on to pre-empt a catastrophic failure.
Anyway – that is only 500kms of towing. Hopefully after a few more miles, I will have a more subconscious understanding of how to drive without paying as much attention to the telemetry. But it will always be nice to have that data there when required.
