Jambers

Nice thread - I thought there were 4 differences:

1) Mapping
2) Inlet Manifold - the 525 is slightly smaller/narrower without swirl flaps
3) Turbo is different
4) The biggest one - the gearbox - all that extra torque could damage it

Best place to look is REALOEM, to see if the part numbers are indeed different....not don that meself yet!!

The comments about performance and value are very key here. I drove all the 5 diesels and whilst I would have the 535d for smiles per miles, the 525d (and may be the 530d - just watch the insurance and ?4k hike if you buy new) is the best combo. The standing start is very quick at all the torque gets to the wheels from only 1300rpm...The engine is amazing! See my other thread on economy...

If you are getting a slightly used one, the 530d has got to be one to look for if you can find one at a similar price to the 525d...

narvselius

There are hardware differences between the two. This was discussed on another forum, where it was stated that there are a lot of differences; as mentoined inlet manifold, turbo, generator, etc etc. So it's not really plug-n-play...

The turbo is
525d: 11657791758
530d: 11657794260

Also, the auto box and the manual box have differnent part numbers whether it is a 525d or a 530d.

Palmo

Afraid not all your information above is correct - I recently did a lot of research on this very subject and did compare many Part No's on RealOEM.

The differences:

1) Mapping - This is obviously one of the main differences.
2) Inlet Manifold - the 525d is slightly smaller/narrower without swirl flaps - Agreed, minus swirl flaps has to be a bonus!
3) Turbo is different - Incorrect, the Turbo AND Injectors are the same on both 525d & 530d.
4) The biggest one - the gearbox - all that extra torque could damage it - Agreed in the case of the Autobox, the 525d is rated at 400NM - the same as the cars power output - theoretically leaving no room for a power increase, whilst the 530d is rated at 600NM from memory, same as 535d. However, the manual gearbox is rated at something like 520NM (again from memory) - the same on both the 525d & 530d.

On point 4 above, the moral of the story for me is, that if buying a 525d, then I personally would avoid the autobox if wishing to remap as this is potentially a weak spot - unlike on the 530d & 535d. However, with the manual box, remapping the 525d isn't a problem at all as it's a stonger box than the 525d Autobox, but is more of a concern on the 530d. In contrast on the 530d & 535d the Autobox is the way to go if wishing to remap. These gearbox comments are purely relating to gearbox strength rather than driving experience suitability. In reality even if a gearbox is rated at 400NM and the cars output is 400NM, there will still be an inherent level of safety margin engineered in.

Dandle

I thought some of the valves in the head are bigger on the 530d as well as the difference in the manifold.

Palmo

Again, some of this information is incorrect.

All information below taken from RealOEM and refers to LCI 525d & 530d models

Turbo - Same
525d: 11657794260 (11657791758 was pre-LCI fitted to the older 2.5d engine)
530d: 11657794260

Intercooler: - Same
525d: 17517795823
530d: 17517795823

Intake Manifold: - Different
525d: 11617799625 (without Flap control)
530d: 11617800585 (Vacuum Controlled)

Injectors: - Different (I was wrong in my previous post)
525d: 13537794555
530d: 13537809194

Gearbox - Auto: - Different
525d: 24007577802 (GA6HP19Z) - rated to 400NM
530d: 24007572498 (GA6HP26Z) - rated to 600NM (I believe)

Gearbox - Manual: - Same
525d: 23007571426 (GS6-53DZ - TJGA) - rated to 530NM
530d: 23007571426 (GS6-53DZ - TJGA) - rated to 530NM

Palmo

I think it's the inlet valves on the 530d that are bigger.....it's all listed on RealOEM.

AlexFW

Retrofit, retrofit!

Jambers

Thanks for the clarifications. I'm even happier now - I don't have any plans to mod anything other than add 172's and then mudflaps to stop the horse manure sticking to the side!!

The car is plenty powerful enough with 197 horses, and the 525 without those swirlflaps makes it less complicated. I'm hoping for 10 years out of mine - hence my other post on longevity of the M57.

narvselius

Sorry, was referring to non-LCI cars... Anyway, thanks for the clarification and that you took the time to check!

Sahil

Damn, there go all my plans to remap! So we 525d LCI owners have no option to quench our hunger thurst if any. Or probably the SpringBooster is the closest you can get, won't increase torque but would it improve the performance 0 to 60 timing at all?

Btw, several 525d LCI's here have had remaps, anyone reported a transmission problem yet ?