MG ZT/Rover 75 Diesel Variant & Versions

[Rincewind]

As some people appear to be interested, I've put together a document that lists all of the variant and version codes used for the Rover 75 and MG ZT/ZT-T diesel engines.

In the document youwill find the codes used to determine what engine tune you have in your vehicle (either 116 or 131ps).

You need to look at your V5 document and at the top there should be 2 lines, one saying Variant and the other saying Version. Match these codes to the document and you should find out if you have what you think you have!

Any problems, drop me a line. I think that I have captured all of the codes, but having gone through documents from 1998, there are quite a few and I may have got a bit number blind!

Nic

[Spike1400]

Nic,

I take it an X-Power 135 stickered car would still be entered in the log book as a 116ps version.

Andy

[Rincewind]

Correct. If the car started life as a 116, then the X Power upgrade will be identified as you say by the sticker. The original entry on the V5 will show it as a 116.

[Staggered]

Hi Rincewind, just checking through my details on the log book and it apppears that my CDTi ZT is the 116ps version - but the supplying dealer assured me that it was the 131ps version.
Where would an X Power sticker be - it sure aint in the log book. Would there be any other distinguishing marks ? I have to say that I'd certainly like more power as it does seem a bit sluggish but maybe I'm getting more used to the car.

[Rincewind]

Hi and welcome to the site.

If you had an X Power sticker, it would be on the "B" pillar next to you on the door slam.

How old is the car? There aren't any other marks to distinguish it really as the tune is in the engine control unit.

If it were a 135, and you had one of the "newer" VIN plates that was a self destructive stick on label (passenger door B pillar) there would be another sticker on your side of the car that would tell you what variant it was i.e. MG ZTT 131 or something to that effect. If there is no sticker, then I would question it or get your dealer to hook it up to the MGR T4 test book and get it to find out what tune it is.

Nic

[Staggered]

Oh Bu**er - it looks like it's a 116 then !
I guess on reflection that it feels like it needs more power now I'm driving it regularly. I can't find any stickers on either B Post so I'm assuming the worst. I intend to go down the Synergy 2 route as everyone who has one seems to rave about it's virtues, and I would welcome a bit more power...not the top end stuff but the torque that you use at everyday speeds would be fine for me.
Many thanks for your reply though - no matter how depressing it is for me !

[Parsec]

Is it right to say the 116 and the 131 are not the same physical engine? Was wondering because the 131 can be chipped higher than the 116 I think?

[Rincewind]

Originally Posted by Parsec

Is it right to say the 116 and the 131 are not the same physical engine? Was wondering because the 131 can be chipped higher than the 116 I think?

The engine is exactly the same bolt for bolt. The only difference is in the calibration and that's it.

Depending on where you start may determine the final result of the power output. A 116 may jump up quite high as there is "room" in the mapping to do it. The 131 may only hop up a bit as there isn't the abilty to do it. It's how the ECU is calibrated.

The 116 is a full BMW unit, the 131 although the same has had the calibration data mucked about with to lift it to 131 and stay within the emissions and smoke requirements/legislation of the engine.

Nic

[Parsec]

Originally Posted by Rincewind

Depending on where you start may determine the final result of the power output. A 116 may jump up quite high as there is "room" in the mapping to do it. The 131 may only hop up a bit as there isn't the abilty to do it. It's how the ECU is calibrated

Ah - I get it.

So if you got a 3rd party remap on a 116ps engine it wouldn't go as high as a 131ps. I thought it was because the 131 engine was updated, but what you're saying is you could take the 116ps engine, get it properly upgraded to 131 via the official update, THEN get that remapped and the end result would be the same between the engines.

[Tootall]

Originally Posted by Staggered

I have to say that I'd certainly like more power as it does seem a bit sluggish but maybe I'm getting more used to the car.

If you are after a power increase then go over and have a look on the 75/ZT Owners Club and get in touch with RoverRon about one of his tuning boxes, i have one fitted to my CDTi ZTT which gives a nice power boost.

[Rob Cavell]

Originally Posted by Parsec

Ah - I get it.

So if you got a 3rd party remap on a 116ps engine it wouldn't go as high as a 131ps. I thought it was because the 131 engine was updated, but what you're saying is you could take the 116ps engine, get it properly upgraded to 131 via the official update, THEN get that remapped and the end result would be the same between the engines.

As far as I know they can all/both be remapped up to about 165bhp see:

http://www.chiptuninguk.com/chiptuning/frames.asp