JTD or JTDm?

I have been looking at GT's and notice that some 06 plates are advertised as JTD and others as JTDm. Did the engine change in 2006 or is it just a new name for the same engine.

The first diesel GT's were JTDs and have 176g/km co2 emissions and the JTDm's have 165 g/km co2 - which makes it cheaper to tax

JTD - 176g - Euro III compliant
JTDm - 165g - Euro IV compliant

Other than mentioned above the are mechanically the same. They both have the 16v Multi Jet engine.

Regards

Rob

Originally Posted by Sensible

I have been looking at GT's and notice that some 06 plates are advertised as JTD and others as JTDm. Did the engine change in 2006 or is it just a new name for the same engine.

This is the question we all wanted to ask, but were afraid to....

p.s. doesn't the new look site look good..!!!!

Originally Posted by Relaxitscool

Other than mentioned above the are mechanically the same. They both have the 16v Multi Jet engine.

Regards

Rob

Having had a quick look at Parker's, I noticed that the JTDm has slightly better mpg than the JTD - apparently something to do with the JTDm's improved ability to vary the rate at which it injects the diesel?

Found a description of the two engines on 'The Workshop' website. This suggests that the engines are not the same, and it is only the later JTDm that has 16 valves. ??

Originally Posted by Sensible

Found a description of the two engines on 'The Workshop' website. This suggests that the engines are not the same, and it is only the later JTDm that has 16 valves. ??

They are both 16V

Just briefly returning to this thread, the JTDm also has lower CO2 emissions to the extent that it falls under a lower road tax band. Saves quite a few £!

I think they just reprogrammed the ECU on the JTDm, the engine is the same

Now I feel either completeley stupid or am going slightly mad!
Sureley the JTD is an 8 valve.. as the JTDM is a 16 valve, the 'M'
stands for 'Multi jet'

The engines are therefore completeley different..

Doesn't the 2.4 JTDm engine have 20v rather than 16?

Originally Posted by cooper1997

Doesn't the 2.4 JTDm engine have 20v rather than 16?

Only because it has a whole extra cylinder as well...

All I know is mine is a JTD and has 8v. was under the impression that the m has 16v

Originally Posted by delta

Now I feel either completeley stupid or am going slightly mad!
Sureley the JTD is an 8 valve.. as the JTDM is a 16 valve, the 'M'
stands for 'Multi jet'

The engines are therefore completeley different..

Nope

The M doesn't stand for Multijet, but for Modificata and the changes are emissions related. The bhp output of the Multijet 16v stayed the same when the m was added. The bhp output of the Unijet 8V raised 5 bhp from 115 bhp to 120 bhp when the m was added. The Alfas in NL also got the diesel particle filter when the m was added, but I don't think that is the same in the other countries.

The JTD engine in the GT is always a Multijet with 16v.

The 147 JDT M (multijet) 8v has 120 BHP.
The 16v engine has 150 BHP.
I believe that the engine is the same but one has 8 valves and the other 16, obviously giving the extra 30 bhp

All 1.9s are all essentially the same engines diferent cylinder heads-either 2 valve/sohc or 4 valve/dohc and the 2.4 is just a 1.9 with an extra cylinder added.

I think we have lost the thread a bit here.

We are talking about the JTD and the JTDm on the GT. They are both 1.9 150bhp engines.

The original question was what the difference was between the two. Some say 8v and 16v, others say they are both 16v.

Some say they are different in emisions, one is 165 and one is 176 g/kg co2. The dealers say that the an 06 JTD is a 165g/kg co2, which turns it all on its head again.

Some say that the later one is a multi-jet or M-jet, but that is how a lot of JTD's are refered to.

Is there not an Alfa technical buff on this forum to definatively tell us the difference between a JTD and a JTDm in a GT.

here here to the above comment as now I am utterly confused

The definitive post on the JTD and JTDm engines in GTs;

There are two variants, both are 16V, both are 150bhp and both are multijet. The early engine had an emissions figure of 176g/kg and is Euro III compliant, the later JTDm (the 'm' standing for modificata) engine had a figure of 165g/kg and is Euro IV compliant.

ok, so how do you tell if a model is an M version or not??? for example if the badges have been removed... as I am buying a GT soon and want the lower emission engine.

[deleted]

Easy answer - input the registration and make into Vehicle Enquiry on the DVLA site and see what they say. Or look at the emissions value on the V5.

Originally Posted by liller123

ok, so how do you tell if a model is an M version or not??? for example if the badges have been removed... as I am buying a GT soon and want the lower emission engine.

Should be stated on the car's V5 certificate.

Any other ID clues, for those of us not based in the UK?

I'm thinking maybe engine number or production date...