TD5 versus M51

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S

sovereign

Active Member
Posts
122
Location
Co Meath Ireland.
Here is a question that maybe the good people of Landyzone could muse over.

A company I worked for supplied me with a Defender 2.5 TD5 Diesel brand new.
This vehicle was grossly overloaded, with huge ladder racks, ladders, tons of copper wire, tools, 2 people etc.
In contrast, is my standard 2.5 litre 2001 Diesel Range Rover.

The question.
The Defender despite all the extra weight had enough power to keep up and merge with traffic no problem, power was never an issue.
My P38 hates hills and slows, pulling out from tee junctions needs loads of room. So what's the difference?

Is it just a technology thing?, or is it a 5 cylinder over 6 cylinder thing?
It's not a weight thing as my company Defender had to be heavier than the P38.

If my P38 had the TD5 power it would be wonderfull.

Edit] just to add the TD5 sounded like a nails in a blender, compared to the purposefull humm of the M51.
 
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Common rail torquey 2.5 versus a 2.5 6 cylinder that's about 10 years older tech.

A TD5 is capable of 200bhp with minor mods and a re-map or even 250bhp with all the bolt on mods and 400-500Nm

A M51 is only good for 180-200bhp before it starts to have problems.
It's just an older engine design really so its kinda apples and oranges

If comparing the TD5 to similar era BMW engine, it would be the M57d30 from the 330 and 530d in which case, the M57 would walk away from a TD5

Fitting the M57 3L diesel is a pretty popular swap for P38 2.5ds too :)



Just to add... in my oppinion, a TD5 sounds nicer than an M51.
M57 is nice alright though! :)
 
sovereign said:
Here is a question that maybe the good people of Landyzone could muse over.

A company I worked for supplied me with a Defender 2.5 TD5 Diesel brand new.
This vehicle was grossly overloaded, with huge ladder racks, ladders, tons of copper wire, tools, 2 people etc.
In contrast, is my standard 2.5 litre 2001 Diesel Range Rover.

The question.
The Defender despite all the extra weight had enough power to keep up and merge with traffic no problem, power was never an issue.
My P38 hates hills and slows, pulling out from tee junctions needs loads of room. So what's the difference?

Is it just a technology thing?, or is it a 5 cylinder over 6 cylinder thing?
It's not a weight thing as my company Defender had to be heavier than the P38.

If my P38 had the TD5 power it would be wonderfull.

Edit] just to add the TD5 sounded like a nails in a blender, compared to the purposefull humm of the M51.
Click to expand...
Sounds like your P38 has a problem. Nowt wrong with the M51 engine although the accelerator has an unusually long travel before anything happens.
 
Datatek said:
Sounds like your P38 has a problem. Nowt wrong with the M51 engine although the accelerator has an unusually long travel before anything happens.
Click to expand...

Correct Keith, if a diesel P38 struggles on hills and does not pull away at junctions it is sick, it needs a coat of looking at.
 
+1 my 2.5 pulls a 1.6t caravan quite happily!
Even at junctions theres not a huge differance however last time I nailed it up a steep hill with the tin tent she overheated :( turned out the viscose fan was fecked
 
I have a m51 and a lad at work has a td5 90 and mine is quicker than the td5 he has a big intercooler and egr bypass but he is getting a remap so il be lagging behind him soon. But I prefer the sound and smoothness of the m51. Your m51 must be sick.
 
Thanks for the replies.
So perhaps my landy is a bit poorly, I'll look into it.

I don't thrash the P38, probably go a little easy on it.
The fact I didn't own the Defender may have been an issue too.

Interesting.
 
No point in being gentle with a M51, pedal to the metal along with frequent engine oil changes.
Engine doesn't wake up until just above 2500rpm, working rpm range 2600 to 4250 rpm, which means stirring the stick in my case...


What we term as economy is about 2800/3000 rpm in 5th...:hysterically_laughi
 
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I thought new Defenders had the Transit 2.2 TDCi engine?

Although I do think there are some rose coloured specs being worn. I must confess I've never driven a fettled diesel P38, but having driven many with standard issue have found the TD5 to be a much nicer unit.
 
Never driven a TD5 so can't comment on them but if I kick my M51 hard it certainly takes off. As for cruising I've never been embarrassed in the mountains.
I've driven STEVE000's chipped one and I'd happily put that against a V8.
 
Saint.V8 said:
+1 Decent engine, we have a 2007 90 at work and it is very torquey and pulls like several trains....awesome tow vehicle, not so comfortable mind!
Click to expand...
Even the old Tddi 2.5 lump in my Transit is a pretty good motor, a map from Vantuner can up the power to about 180bhp:eek: If only I could mate it to a ZF4HP24 and drop it in the P38:)
 
Like the chap who thought he had gone blind, until it was pointed out to him his hat was just too big.
Bit of a result, turns out yes, I was being too gentle with the pedal.
Give her a good prod and yes off she goes, still no TD5, but wow turns out she can pick up her skirt and go.
Won't be doing it too often mind, but who knew?:):)
 
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sovereign said:
Won't be doing it too often mind, but who knew?:):)
Click to expand...

If you want a clean exhaust reading for MOT's and a sweet running engine, driving them hard is the answer.

Sometimes I drive mine on/near the engine limiter for a short while through the gears (manual gearbox in mine), its amazing how much crap is held in the exhaust due to non-use of maximum engine rpm.

I can induce a smokescreen a battleship would be proud of at times (so handy, when some young cock is up your arse especially in a soft top...;)....:D), if I've been forced to drive slowly around town for a while. Its like the engines is coughing and wheezing then its clears its throat and rewards you.
 
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sovereign said:
Like the chap who thought he had gone blind, until it was pointed out to him his hat was just too big.
Bit of a result, turns out yes, I was being too gentle with the pedal.
Give her a good prod and yes off she goes, still no TD5, but wow turns out she can pick up her skirt and go.
Won't be doing it too often mind, but who knew?:):)
Click to expand...
The off road bias of the accelerator is the main reason that folks think the M51 has no go, now if you had driven a Daihatsu 4Track, a Pajero and a Hyundai galloper before you drove the P38 diesel you would really know the meaning of slow;)
 
zzr1200 said:
If you want a clean exhaust reading for MOT's and a sweet running engine, driving them hard is the answer.

Sometimes I drive mine on/near the engine limiter for a short while through the gears (manual gearbox in mine), its amazing how much crap is held in the exhaust due to non-use of maximum engine rpm.

I can induce a smokescreen a battleship would be proud of at times (so handy, when some young cock is up your arse especially in a soft top...;)....:D), if I've been forced to drive slowly around town for a while. Its like the engines is coughing and wheezing then its clears its throat and rewards you.
Click to expand...
Never seen any smoke out of mine even reving to the limit in second up an Alp:)
 
Mine makes an interesting smoke screen that is only really visible at night when I absolutely nail it. During the day it cannot be seen, but once it gets dark out and the lights are on. No doubt something expensive is wrong.

But she goes well, I've taken many the nob at traffic lights without really trying and the motor does sound lovely when you're putting some load in it, going up a hill for example. Just makes me yearn for a V8 though. :(
 
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