My JTD has gone in for a service and I have been given a multijet (1.3 16v 70bhp) as a courtesy car. An ideal opportunity to see the advances in diesel technology. So far I have noted;

• The multijet is much quieter at idle with no vibrations through the car at all. There is a gentle 'hum' in the distance but it is not unpleasent. The JTD betrays its diesel roots at idle.
  
  The clutch in the multijet is much lighter and it feel like a petrol cars (i.e. no vibration). The JTD clutch has always been a bit 'agricultural'.
  
  However
  
  It sounds like a moronic cow when you accelerate. It is most off-putting.
  
  The turbo is like a 'switch' with huge-lag. At about 1800rpm it suddenly wakes up, or about 1 second after hitting the throttle when cruising. It can be fun the first few times, but gets tiresome very quickly and makes smooth driving a pain. The JTD has power at all times.
  
  The turbo lag is a pain on hills. On the A1M I found myself loosing speed when I came to an incline, having to bury the throttle to keep up with traffic. The JTD never has a lag problem and laughs at inclines.
  
  The JTD will crawl in traffic with no contact on the throttle, the multijet went into 'spasm' when I tried this and nearly stalled.
  
  I did not expect performance to be as good as the JTD (down on power and torque although it is about 100kg lighter) but I found it really wanting for performance and not a patch on the JTD (the car has 6000 miles on the clock so it may need a little more time to loosen-up but it won't make that much difference)
  
  The economy of the multijet (on the basis of the trip computer) seems little different to the JTD

All in all, more refined for sure but if I was trading in a JTD ELX for a multijet Dynamic (an apparent replacement) I would be less then chuffed. the 1.3 16v 90bhp model (when it comes out) will undoubtably answer the performance short-fall, but I can't see it resolving any of the other problems with 'turbo-lag' potentially being worse

I suppose it should be noted that using a 1.3 TD is about the lowest any small car has used before. Also, 70BHP sounds like a low spec MJTD? I am sure they must have a more powerful 1.3 MTJD?

Surprised about the MPG, sure you're not trying to get as much as it from your 1.9? For example, the 1.5DCi Clio (80BHP version I believe though they make a 65 and a 100BHP version too) does 109 MPG at 56mph in 5th! I would expect the punto to be able to something similar with such a tiny engine!

Sorry, saw your comments about the 90BHP version now so ignore a few of my comments.

The Clio (65, 80 and 100bhp) does about 65mpg on the extra-urban and the 1.3 multijet Punto is about the same. However, 'real world' is a different matter. My JTD is supposed to be able to get 70mpg on the extra-urban and I got it once by driving like a Vicar, but it was not a fun experience.

I drive the JTD 'normally' and get 53-55mpg on each tank and although the trip computer is never 100% acurate, it is usually in the right ball-park. The multijet was showing 51.4mpg so assuming it will get a little better with miles I would suggest it is the same as the JTD.

The JTD, whilst being a bigger engine is helped by two things. Firstly, it has effortless performance so you never need to thrash it in order to make progress. This is not true of the multijet, with that turbo lag being a pain. Also, the JTD has much taller gearing, so 80mph is about 2500rpm, where as the multijet is doing 3000rpm at the same speed.

I've always thought it strange how the press rave about this engine but I've not heard any fantastic reports about it from owners.

So does the MJTD come to be more expensive?

If so, it seems the engine is 1) Slower 2) lacking power 3)has no fuel economy increase compared with the JTD. So, what's the point? Maybe the 16v version will fix it then.

The 1.5Dci doing 109MPG was some form of unofficial world record.

My girlfriend has a Corsa with this engine, and I'm sorry but I disagree, I think its a cracking little engine.

Its quiet, refined (more so than my Stilo), economical and I think feels lively.

Yeah, sure on the open road my Stilo would have it for breakfast, but round town its great, and it definitely has the legs on the majority of small petrols.

Admittedly, there is a fair bit of lag, but you're going to expect that, with such a small CC its going to be relying more heavily on the Turbo.

Oh, I'm sure the 70bhp version is a 16v, I seem to remember noting this when I was looking at getting a Punto, because I was miffed the 1.9MJTD I was going to get was only 8v.

As I said earlier in the post, the 1.3 70bhp is a 16v.

Negotiator, The 1.3 multijet is more expensive than the old JTD. Fiat used to charge a £500 premium over the 1.2 16v for the JTD, the multijet is £900 extra.

My Dad tried it in the Corsa and he also found it to have 'flat spots' (by which I think he meant laggy). There is nothing really wrong with the engine, it just isn't a patch on the JTD in many ways.

I went out last night and reset the trip computer. When cruising I got it up to 114mpg (and that was on 'trip' rather than 'instantaneous' setting), but as soon as I used the throttle (not heavily, just to accelerate with traffic) this dropped like a stone and the average went back to 51.4mpg. I also noticed it has odd gearing for UK roads. At 30mph 3rd gear seems to short, so you change-up into 4th and it can barely pull and vibrates heavily if you try to tweak the throttle. I think it is the on/off turbo that is the problem because below 1800rpm there is nothing

While it is no power-house, at least it is willing to rev to about 5000rpm quite hapily

JTD Monkey said:

While it is no power-house, at least it is willing to rev to about 5000rpm quite hapily

Click to expand...

I find its not really worth revving it though, short shifting but keeping the turbo on boost seems to work best.

James M said:

I find its not really worth revving it though, short shifting but keeping the turbo on boost seems to work best.

Click to expand...

That is what I tried first time out and just kept getting caught in turbo-lag-no-mans-land. But it does rev more freely than the JTD (that'll be light weight and 16v doing that).

There is also an annoying 'mooing' noise emmitted from the radio whenever you put your foot down. And it is also a sharp reminder that despite having pretty good standard speaker systems, Fiat head-units are a pile of poo

My dad has the stilo jtd and the punto multijet. Both are absoluetly crcking engines. The best around. The punto doesn't like it being lazy. Simply loves it when you put your foot down and change the gear on boost. all you feel is the lovely force.
Also, the 'mooing' sound is probaly caused by the engine ecu which is placed directly in front of the radio (lookin under the bonnet, straight in front- middle). we always get above 50mpg even when most of the time it is being pushed shall we say 'swiftly'.

The fact is that most people have diesels as they can be driven lazily when you want to, less gear changing etc. having to constantly "raz" changes the driving style IMO.

And there was me thinking people bought diesels because you can get a powerful 2.0TD to return 70mpg!

What I meant was "one of the reasons"....

You have so much torque normally you can get away with pulling away in 3rd for example rather than changing down to 2nd and not having the same affect as with a petrol.

I actually prefer driving diesels due to the power curve and the relative ease of driving one tbh.

lalli said:

Also, the 'mooing' sound is probaly caused by the engine ecu which is placed directly in front of the radio (lookin under the bonnet, straight in front- middle).

Click to expand...

You're right, I eventually worked it out by turning the radio off. Then all I could hear was the manky engine clatter...

This also made me realise the standard Fiat stereo is a joke. It couldn't hold a station and the noise was 'tinny'. I know the speakers are pretty good so it must be the head unit...

However, glad to be back in my JTD, where I belong

Intersting read.I think it will be better to compare the 90bhp 1.3 mjtd to the old 1.9 jtd when it comes out. Clearly they have moved the game on a bit tho, especially in terms of refinement and it is the smallest diesel in production in the world. Although vw did have a 1.2 3 cylinder they used in the lupo in europe which I think broke a record for mpg, but even the vag 1.4 only has 3 cylinders where as the 1.3jtd has 4 it is only really smaller in terms of cc. I think common rails have finally caught up with the pd's.

Common rails were always ahead on refinement

I suspect the 90bhp 1.3 multijet will be a nice motor, but the 70bhp engine is a bit below par

Come on then there must be some others apart from me who don't know... briefly what is the difference between a multijet and a JTD?

probably not the most qualified to answer but, I think multi jetproduces up to five squirts of very high pressure fuel per cycle depending on how open the throttle is, it therefore produces a cleaner and better detonation, which in principle makes it smoother,economical and powerul.