2.5 or 2.7Tdi - Which is best ?

[Resin Rocket]

I originally posted regarding the 2.7Tdi, but there are some nice specd 2.5's for sale and wondered if the 2.7 is a significantly better engine or not.

Are the 2.7 and 3.0 basically the same engine (other than capacity) and the 2.5 based on an older design ? Am I right in thinking that the 2.5 has belt driven cams and the 2.7 chain driven cams ?

Can the V6's easily be retrofitted with cruise like the 4pots ?

Apologies for all the questions but don't know a lot about Audis :confused: so any info is much appreciated.

[adamss24]

I think you allready answered your questions ! Yes, the 2.5 tdi is an older design, has a Bosch VE 44 rottary pump and is pretty much bulletproof apart from failing injector pumps and soft cams. The 2.7 and 3.0 are common rail and very good indeed. Power has increased as well and they were fitted on quattro chassys due to the high torque output. The front wheel drive chassys cannot put the power down reliably. The engine block is the same and they have geared driven cams but a toothed belt to drive the high pressure pump. All drive-by-wire vag cars are easy to convert to cruise control, it just needs the stalk, wiring loom and cruise activated in the ECU. There are companies who can do it wich advertise on ebay with prices ranging from 170 to 250 quid. If you can afford the bills, go fot the later 3.0L tdi quattro, it has 240 bhp and its a beast of an engine. The 2.7 is just a bit smoother and will return marginally better ecconomy. I suggest you test drive all and see wich one fits the bill. Avoid at all costs the multitronic in the 2.5 tdi. If you go for the quattro, it will be a better gearbox but with a conventional torque convertor. The 2.7 and 3.0 tdi quattros both remap well but not many tunners will remap the ones with manual gearboxes as they tend to munch the clutch. It seems that the automatic ones have less problems. The 180 Bhp 2.5 tdi as fitted to quattro models remaps safely to 240 Bhp, after wich it will munch the clutch. The gearbox is strong enough but wont play ball if the torque is upped much over 450Nm. I have seen snapped driveshafts on remapped models. Sachs does an organic clutch kit for the v6 AKE engines wich can safelly put over 500Nm without slipping. Dont know how well the 3.0 will last but i have seen 2.5 tdi with over 600K miles. I did owned 2.5 tdi in the past and they are good, if not as ecconomical as i wanted to be. That noise alone is very nice. The common rail engines are quiet and dont sound like a diesel engine at all, even on tick-over.

[Resin Rocket]

Thanks for the info :biggthump

[Terry S]

. Sachs does an organic clutch kit for the v6 AKE engines wich can safelly put over 500Nm without slipping.

Do you have the correct P/N for this clutch please, as I want to replace mine before having a remap done to my 3.0 Quattro.

[adamss24]

You will need to get in touch with Sachs as they dont list a 3.0L quattro on the website. AKE is the 180Bhp 2.5 tdi engine !

[Terry S]

Thanks for that, I wonder if the Q7 clutch is the same.