Thread: Anyone run an overdrive on their TD5 Defender?

Omaroo here is the text from the website re price of the unit:

GKN Land Rover Overdive for a limited period is available for £799 plus vat,[whilst stocks last] we would be please to fit the Overdrive for you in our workshops - please call for price, curtosey vehicle available whilst your fitment takes place.
Place you order now, whilst we have stock 01769 550900

From www.devon4x4.com, am pretty sure this is the right unit.
Thats $1938.00 plus shipping plus import duty (import duty and shipping surely are not worth $2000.00??) - am fairly sure fitting these units up is also not too difficult.

If the economy improved that would be a bonus - intend to do a lot of touring in the vehicle and would like to be able to do so without the engine screaming its head off - if this can be achived with the gearset mod mentioned I may follow this route.

<div class='quotetop'>QUOTE</div><div class='quotemain'>The only time that a diesel uses significantly more fuel per horsepower is when they are overfuelling to get the last few horsepower for that rpm - but this does not happen with modern diesels like the TD5.[/b][/quote]

I think this exactly explains Tombraider's 15l/100km with his remapped ECU. It is why I am also interested in the EGTs from any overfuelling.

But you would have to think that a considerable drop in cruising rpm (and therefore fueling) would also have a big impact on consumption. :?

<div class='quotetop'>QUOTE</div><div class='quotemain'>intend to do a lot of touring in the vehicle and would like to be able to do so without the engine screaming its head off - if this can be achived with the gearset mod mentioned I may follow this route.[/b][/quote]

Might be worth also considering a noise deadening kit. Pretty sure some people here have invested in them. Might be worth dropping a PM to 'rmp'.

I've just had the 1.2Q gears fitted. Haven't been far on the open road yet to determine any difference in consumption.

But it is so much quieter its not funny. Instantly noticable. Well worth it.

Regards
Max P

Originally posted by dhumphri
Omaroo here is the text from the website re price of the unit:

GKN Land Rover Overdive for a limited period is available for £799 plus vat,[whilst stocks last] we would be please to fit the Overdrive for you in our workshops - please call for price, curtosey vehicle available whilst your fitment takes place.
Place you order now, whilst we have stock 01769 550900

From www.devon4x4.com, am pretty sure this is the right unit.
Thats $1938.00 plus shipping plus import duty (import duty and shipping surely are not worth $2000.00??) - am fairly sure fitting these units up is also not too difficult.

If the economy improved that would be a bonus - intend to do a lot of touring in the vehicle and would like to be able to do so without the engine screaming its head off - if this can be achived with the gearset mod mentioned I may follow this route.

AU$2,287 including VAT. Would we need to pay that if we are having it exported?

You should not have to pay VAT, but the boys at Customs might want to hit you with a duty as it comes in. :wink: I think anything over $800 is meant to be dutyable??? :?

Tusker where did you source the transfer case gears and how expensive was the whole job if you don't mind me asking. Daz

A secondary effect that I did not consider is that unless you change down, the overdrive effectively limits the available power (and hence fuel consumption), although the effect of this will be very dependent on road conditions. For example, on the Newell Highway (straight and flat) I would expect no effect, whereas on the New England (hilly and bendy), a lot.
Most drivers would not bother to change down, but would put up with slower acceleration out of curves and accept slowing a bit on hills rather than change down.

My comment about modern diesels not overfuelling does not necessarily apply to one with remapped engine controls, although in most cases they will also have increased boost so specific fuel consumption will not have changed much. But if additional power is there it tends to be used, particularly by those types that go to the expense of doing it in the first place, and this additional power shows up on the fuel bill (and usually on brake wear as well).

Whilst mine isn't a Td5, it is a 200Tdi, I did a similar thing to it.

The transfer case gears where stuffed after a trip through the Oodnadatta, so I replaced the gears with Maxi-Drive reduction and Disco high-range. I sourced all of the parts from Maxi-Drive costing around $3,200.

It did make a big difference, however up here in the NT I found that my fuel consumption went through the roof. But speeds of up to 140km/h where easily reached. I also did find though, that 5th gear is now definetely only an overdrive gear - it basically has no pulling power at all.

When I relocated it down to Tassie, where the speed limits apply - the fuel consumption was down to around 8.5 - 9 litres per 100km's. That is driven fairly hard in places - as it isn't exactly flat! I really don't use 5th gear that much unless I'm on the highways, as it's a waste of time engagin under 90km/h.

Personally, I'd recommend this course of action over an overdrive unit - because basically you get the best of both worlds. I now have a vehicle that crawls slower than a baby, and one that also cruises quite comfortably, and a lot quieter.


Cheers
Chris