Hi I purchased a new D Max 2017 has now done 40000klms to tow my caravan approx 3000kgs I purchased the auto 6 speed and have found some problems only when towing the converter lock is computer controlled not locked at a certain speed you can lock trans in manual mode but you can't lock the converter so if the computer dosen't want lock you have no choice the result is that if conditions are perfect or you have a tail wind cruising around 90 kmh you will get around 13/14 lph and everything is really good however if conditions aren't perfect or there is a head wind your fuel consumption will go to around 18/20 lph because when travelling in drive the trans will stay in 4th most of the time and engine rpm is 2000/2300 if you wish to keep converter locked you need to travel at around 105 kmh locked in 5th then the wind resistance is high causing the high fuel consumption these engines are tuned to be very economical when under 2000 rpm but not so great when over 2000 rpm Isuzu utes Australia have put out a reflash for the trans mine has been done did improve really only when conditions are good also Isuzu utes Aus tell me that nothing can be done to lock converter which is disappointing as there is not much else out there that is as good so be aware when you are buying the new model 6 speed auto I guess the manual could be a good choice if others have experienced similar I would like to know
Dougwe said
10:24 PM Jan 31, 2019
I notice you have been around since November, Bill, but I haven't seen you so welcome to the gang, enjoy here and out in the playground.
I think your Dmax is a little similar to my Collie so have you tried towing in selective shift (manual). I tow a lot in manual as I can have full control then. Works for me anyway.
I get around 10lts per 100km not towing and around 13 when towing 2.7t. The Collie is loaded at all times as I am full time GN.
Might be worth a try, nothing to lose.
-- Edited by Dougwe on Thursday 31st of January 2019 10:24:40 PM
Tones said
05:43 AM Feb 1, 2019
Bill, we have a 2017 Dmax and tow a van at 2.5T. I have fitted a Scan Gauge II and have monitored the performance of the vehicle using different methods of driving. My first concern was to monitor the transmission temp when towing.
Isuzu recommend that you leave the transmission in "D" and let it do its own thing. After much experimentation, I have found that if you lock manually in 4th gear after getting out of town, sit on about 90 Km/hr (or whatever is suitable for the conditions), you can use cruise control on the flat and get a good result. Revs. at that speed are about 2400 but the big bonus is that the auto trans. drops on average about 17 degrees lower than leaving it in "D". Our average fuel burn is about 14 l/100Km using the above method which is quite acceptable to us and much better than our previous vehicle (BT50). On long runs, it is rare for the gearbox to change down out of 4th. gear unless on a steep climb. This method also makes maximum use of the torque band of the Euro 5 engine.
On the flat with easy driving conditions or coming off long hills etc. "D" is our choice.
If you look in the manual, you will find a short statement about towing in manual but it does not address all scenarios. Isuzu also allow 350Kg on the ball (but don't endorse or recommend the use of WDH - like most other manufacturers) but I would not like to be driving our vehicle under those circumstances. I would need to grow about another foot taller to see over the dash at the very least!
To each his own but the above works well for us and I know that I am not cooking the Auto transmission.
Hope my comments are of some help.
Tones
travelyounger said
10:04 AM Feb 1, 2019
Hi I have had my Max since new June 9 2017 towing 2.8 ton and always lock into 4 th gear manually. I find that the transmission is not working through the gears all the time. I travel 90 to 100 km per hour and if have a tailwind might go into 5th gear. Sometimes on a long steep hill the transmission light will come on so just drop a gear and light should go off. When driving the without van I usually lock in 5 th I don't use 6 to often. Cheers
scoota said
12:17 PM Feb 1, 2019
We have a 2018 Dmax auto. When we first drove it with the van we started using the gears going up hills etc however the gearbox light came on a few times only for a few seconds, I spoke to Isuzu and they recommended we only use D as previously mentioned in one of the posts, since doing this the lights have never come on so can only assume that all is well with temperatures. I am though interested in Isuzu not recommending the WDH and why? only the caravan centre we purchased from not only recommended one They supplied and installed it.
We have averaged 15.7L per 100.
Combined weights about 5.6 ton.
Ron-D said
04:47 PM Feb 1, 2019
I have a Mux 6 speed auto the stock towbar is not well made.And there has been issues with it cracking,the Haymen Reece bar is built to handle the weight and stress in my opinion and Thats what people fit to there Isuzus,our van is only 2.5 ton loaded and I tow every where in drive not in manual and the car does it very well indeed...
-- Edited by Ron-D on Friday 1st of February 2019 04:51:02 PM
Wasley said
12:55 PM Feb 2, 2019
Hi Thanks for the welcome and the replies for any of you that have a 6 speed Auto D Max you appear to be having similar problems these engines are tuned to run under 2000 rpm and when they do they achieve 12 to 14 lph towing and around 8to9 lph when not and they will do so very easily in 5th gear lock except for the converter lock which if you leave out of converter lock the trans overheats very quickly and it is difficult to tell when they are out of converter lock unless you know the signs. Before I purchased our D Max I was lucky enough to borrow a 2016 Auto 5 speed and we towed our van from York to Dumbleyung and back and York to Kalgoorlie and back and averaged 13.5 lph for both trips with that in mind I purchased the 2017 6 speed thinking it would be better to find when it was new it was diabolical even without the van on every time it came to the slightest hill whilst in cruise control it would jump straight from 6th to 4th realise it had made a mistake and go back to 5th and generally be happy however if your climbing a long hill in cruise control it still will jump from 6th to 4th then change up to 5th only to change down again to 4th it will do this for the entire climb up and down however if you lock it in 5th it will stay there very happy and climb all day long am I being to pedantic or is there problems on a good day when towing this vehicle is close to perfect even when in drive it will achieve near magic but in hills and with a slight headwind it is no better than all the others out there and I don't think you should have to run in 4th gear as you are defeating the purpose of fuel efficiency and the engine torque which to memory is 1600 to 2000 rpm and in 4th at around 90/95 you are doing 23/2400 rpm and 20 + lph. If you are unhappy at all IUA have put out a reflash for 2017 to bring them to the same as the 2018 which if you have driven both there behavior is quite different trans wise I have had a conversation with the tech team at IUA they gave me some things to try which I have crossing from west to east where I am currently there ideas do help some of time as these trans are intuitive and I must say it has sometimes surprised me with its antics however the problem with the converter lock is obvious when the conditions are not perfect. I have fitted a wind deflector which has given a subtle improvement in some conditions and also keeps the front of our van cleaner the next thing I will try are some of the vortex generators
Regards to all Bill Morley
Ron-D said
09:18 AM Feb 3, 2019
There must be something wrong with my six speed Mux I just leave it in auto when towing no problems perfect...
Aus-Kiwi said
10:45 AM Feb 3, 2019
The thing is you dont know what is going on ? . But a Manu wont recomend you do anything . As they would be admitting an issue . I find if it skips gear to gear or labours in certain conditions . I shift down or adjust the trottle to prevent too much shifting . Lighter thottle at slight higher rpm gives better fuel consumption .
Rusty W said
01:25 PM Feb 3, 2019
Hi Bill, a caravan of 3 tonne would be a full height van and creates a lot of drag. Your motor might be tuned for economy under 2000 rpm but not a lot of power at those revs. You need power to shift your weight and that takes fuel and more revs for the motor to develop that power. 18/20 litres per hundred
is not that bad for a 3 tonne van. Your trying to labour your engine, but the computer won't allow it.
There are lock up kits for Toyotas and other brands, so maybe check with transmission specialists maybe they make one for your car.
regards Russell
aussie_paul said
05:31 PM Feb 3, 2019
IMHO, when towing the more time the auto spends in overdrive the more it is going to cost eventually.
Aussie Paul.
Wasley said
08:28 PM Feb 4, 2019
Thanks Russell but we borrowed a 2016 dmax 5 speed with the lower torque engine and that towed the same van around 1500 klms and averaged 13.5 lph which means the new model with the 6 speed trans and higher torque is a step backwards which shouldn't make sense however as you have no control over the converter lock this car spends most of it's time in 4th gear unless you take it over 100 kph then it will stay in 5th gear lock however the wind resistance increases the fuel usage to around 18lph which if looked at logically decrease the speed decreases the drag decreases fuel usage which of course does happen until the converter lock drops out and the engine rpm goes to around 2300 rpm oh and at 105kph locked in 5th engine rpm is at 1800 and it will generally stay around the hundred kph mark with no probs
Walkabout man said
03:17 PM Apr 10, 2023
Hi there I have a 2015 dmax I always tow In manual mode in 4 gear I found the vehicle responds so much better I only have a 5 speed box but it handles towing our 24ft van easily and is best sitting at 90kph
Warren-Pat_01 said
05:01 PM Apr 10, 2023
Hi Wasley,
I have a 2019 D-Max & tow a lighter van than yours (2000kg) but like Tones, I fitted a Scan Gauge to monitor the temperature of both the coolant & the transmission. Since doing that, I have also fitted a transmission cooler (from Wholesale Automatics) as well. Living in the tropics means that the transmission runs hotter.
I tow according to the transm temperature now - in D, in 4th or 5th locked up.
Of course the dealer was most unhelpful - "you'll void your warranty", "put it in D & let the car do its thing," "you don't have to change the transmission oil." Well they are on the business of selling new cars, spare parts & service - NOT preserving the mechanicals in a car.
I had the transm fluid changed when I had the cooler added at 43000kms (is coming up for the second change) & the temperature rarely touches 100 degrees (a common thing before - up to 120 degrees).
I believe the transmission is also used in some Toyota 4wds so it should be tough enough. Have a look at the Ozisuzu forum, a chat with Wholesale Automatics in Victoria.
Hi I purchased a new D Max 2017 has now done 40000klms to tow my caravan approx 3000kgs I purchased the auto 6 speed and have found some problems only when towing the converter lock is computer controlled not locked at a certain speed you can lock trans in manual mode but you can't lock the converter so if the computer dosen't want lock you have no choice the result is that if conditions are perfect or you have a tail wind cruising around 90 kmh you will get around 13/14 lph and everything is really good however if conditions aren't perfect or there is a head wind your fuel consumption will go to around 18/20 lph because when travelling in drive the trans will stay in 4th most of the time and engine rpm is 2000/2300 if you wish to keep converter locked you need to travel at around 105 kmh locked in 5th then the wind resistance is high causing the high fuel consumption these engines are tuned to be very economical when under 2000 rpm but not so great when over 2000 rpm Isuzu utes Australia have put out a reflash for the trans mine has been done did improve really only when conditions are good also Isuzu utes Aus tell me that nothing can be done to lock converter which is disappointing as there is not much else out there that is as good so be aware when you are buying the new model 6 speed auto I guess the manual could be a good choice if others have experienced similar I would like to know
I notice you have been around since November, Bill, but I haven't seen you so welcome to the gang, enjoy here and out in the playground.
I think your Dmax is a little similar to my Collie so have you tried towing in selective shift (manual). I tow a lot in manual as I can have full control then. Works for me anyway.
I get around 10lts per 100km not towing and around 13 when towing 2.7t. The Collie is loaded at all times as I am full time GN.
Might be worth a try, nothing to lose.
-- Edited by Dougwe on Thursday 31st of January 2019 10:24:40 PM
Bill, we have a 2017 Dmax and tow a van at 2.5T. I have fitted a Scan Gauge II and have monitored the performance of the vehicle using different methods of driving. My first concern was to monitor the transmission temp when towing.
Isuzu recommend that you leave the transmission in "D" and let it do its own thing. After much experimentation, I have found that if you lock manually in 4th gear after getting out of town, sit on about 90 Km/hr (or whatever is suitable for the conditions), you can use cruise control on the flat and get a good result. Revs. at that speed are about 2400 but the big bonus is that the auto trans. drops on average about 17 degrees lower than leaving it in "D". Our average fuel burn is about 14 l/100Km using the above method which is quite acceptable to us and much better than our previous vehicle (BT50). On long runs, it is rare for the gearbox to change down out of 4th. gear unless on a steep climb. This method also makes maximum use of the torque band of the Euro 5 engine.
On the flat with easy driving conditions or coming off long hills etc. "D" is our choice.
If you look in the manual, you will find a short statement about towing in manual but it does not address all scenarios. Isuzu also allow 350Kg on the ball (but don't endorse or recommend the use of WDH - like most other manufacturers) but I would not like to be driving our vehicle under those circumstances. I would need to grow about another foot taller to see over the dash at the very least!
To each his own but the above works well for us and I know that I am not cooking the Auto transmission.
Hope my comments are of some help.
Tones
Hi I have had my Max since new June 9 2017 towing 2.8 ton and always lock into 4 th gear manually. I find that the transmission is not working through the gears all the time. I travel 90 to 100 km per hour and if have a tailwind might go into 5th gear. Sometimes on a long steep hill the transmission light will come on so just drop a gear and light should go off. When driving the without van I usually lock in 5 th I don't use 6 to often. Cheers
I have a Mux 6 speed auto the stock towbar is not well made.And there has been issues with it cracking,the Haymen Reece bar is built to handle the weight and stress in my opinion and Thats what people fit to there Isuzus,our van is only 2.5 ton loaded and I tow every where in drive not in manual and the car does it very well indeed...
-- Edited by Ron-D on Friday 1st of February 2019 04:51:02 PM
Hi Thanks for the welcome and the replies for any of you that have a 6 speed Auto D Max you appear to be having similar problems these engines are tuned to run under 2000 rpm and when they do they achieve 12 to 14 lph towing and around 8to9 lph when not and they will do so very easily in 5th gear lock except for the converter lock which if you leave out of converter lock the trans overheats very quickly and it is difficult to tell when they are out of converter lock unless you know the signs. Before I purchased our D Max I was lucky enough to borrow a 2016 Auto 5 speed and we towed our van from York to Dumbleyung and back and York to Kalgoorlie and back and averaged 13.5 lph for both trips with that in mind I purchased the 2017 6 speed thinking it would be better to find when it was new it was diabolical even without the van on every time it came to the slightest hill whilst in cruise control it would jump straight from 6th to 4th realise it had made a mistake and go back to 5th and generally be happy however if your climbing a long hill in cruise control it still will jump from 6th to 4th then change up to 5th only to change down again to 4th it will do this for the entire climb up and down however if you lock it in 5th it will stay there very happy and climb all day long am I being to pedantic or is there problems on a good day when towing this vehicle is close to perfect even when in drive it will achieve near magic but in hills and with a slight headwind it is no better than all the others out there and I don't think you should have to run in 4th gear as you are defeating the purpose of fuel efficiency and the engine torque which to memory is 1600 to 2000 rpm and in 4th at around 90/95 you are doing 23/2400 rpm and 20 + lph. If you are unhappy at all IUA have put out a reflash for 2017 to bring them to the same as the 2018 which if you have driven both there behavior is quite different trans wise I have had a conversation with the tech team at IUA they gave me some things to try which I have crossing from west to east where I am currently there ideas do help some of time as these trans are intuitive and I must say it has sometimes surprised me with its antics however the problem with the converter lock is obvious when the conditions are not perfect. I have fitted a wind deflector which has given a subtle improvement in some conditions and also keeps the front of our van cleaner the next thing I will try are some of the vortex generators
Regards to all Bill Morley
There must be something wrong with my six speed Mux I just leave it in auto when towing no problems perfect...
is not that bad for a 3 tonne van. Your trying to labour your engine, but the computer won't allow it.
There are lock up kits for Toyotas and other brands, so maybe check with transmission specialists maybe they make one for your car.
regards Russell
IMHO, when towing the more time the auto spends in overdrive the more it is going to cost eventually.
Aussie Paul.
I have a 2019 D-Max & tow a lighter van than yours (2000kg) but like Tones, I fitted a Scan Gauge to monitor the temperature of both the coolant & the transmission. Since doing that, I have also fitted a transmission cooler (from Wholesale Automatics) as well. Living in the tropics means that the transmission runs hotter.
I tow according to the transm temperature now - in D, in 4th or 5th locked up.
Of course the dealer was most unhelpful - "you'll void your warranty", "put it in D & let the car do its thing," "you don't have to change the transmission oil." Well they are on the business of selling new cars, spare parts & service - NOT preserving the mechanicals in a car.
I had the transm fluid changed when I had the cooler added at 43000kms (is coming up for the second change) & the temperature rarely touches 100 degrees (a common thing before - up to 120 degrees).
I believe the transmission is also used in some Toyota 4wds so it should be tough enough. Have a look at the Ozisuzu forum, a chat with Wholesale Automatics in Victoria.