Comparison between 1.2 DIG-S and 1.2DIG-T

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jet
Posts: 69
Joined: Mon Apr 06, 2015 7:48 am

Post by jet »

SplanK wrote:You guys are taking as though you should have instant power. That sort of performance from a boosted engine only really comes from a supercharger (although those start to run out of effort at high rpm...), or an engine fitted with a small turbo (again, you run out of effort at high rpm and choke the engine....)

Although turbo engines have been around for a while, most people will not have had access to them due to cost or worries about reliability. Now that they are more common due to regulations almost forcing turbo engines on people, people are not used to the characteristic of them and expect to drive the car the way they drove a NA engine.
Thank you for the detailed post, SplanK :-)

Sorry for my off-topic, but talking about superchargers, I am curious how the supercharged 3 cyl 1.2 DIG-S in the Micra/Note compares to the 4 cyl 1.2 DIG-T in the QQ?
Never had the chance to drive a 1.2 DIG-S, only the NA 3 cyl 1.2 DIG, which compared to my previous GA14DE is a disaster IMO.
Unfortunately the 1.2 DIG-S Note was a bit pricey so I went for a 1.5 dCI QQ. Getting to grips with it took some time, especially low rev city driving, where I found the old GA14DE to be much more friendly. I never believed I could stall a diesel engine, and guess what - all my friends driving NA petrol engines who tried the 1.5 dCi for the first time, also stalled it :)
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Deleted User 759

Post by Deleted User 759 »

Hi Jet - I have split your comment from the original thread into here rather than taking the other off topic.

For notes for others. The 1.2 DIG-S engine is available in the Micra and Note. Its a 3 cylinder engine with a super charger bolted to it. Why a supercharger instead of a turbo? Nissan opted to do down the road of using a miller cycle which essentialy leaves the intake valve open during part of the compression stroke. The supercharger acts like a one way valve preventing loss of pressure. Engine compression ratio is 13:1, however due to the intake valve remaining open, the ratio is a virtual 10:1 (if memory serves me correctly) like most boosted engines. I have read that the engine is able to change between otto and miller cycle depending on conditions and will automatically control the supercharger. This engine is more Nissan than Renault

The 1.2 DIG-T engine is available in the QQ, Juke and Pulsar. Its a 4 cylinder engine with turbo. Runs on standard otto cycle and other than direct injection, nothing special about the engine. This engine is more Renault (based on the TCe engine) than Nissan, in fact, I have yet to find a Nissan stamp on mine!
Deleted User 759

Post by Deleted User 759 »

Right in response to the original post.

I have both, 1.2 DIG-S in a 2012 year Micra and 1.2DIG-T in the 2014 QQ. .

Yes, in a straight line, flat, same driver, no extra weight, the Micra would win in a drag race. The Micra is a light car, and the power output of the engine is just shy of the QQ. The Micra isn't the fastest car in the world but its fun to drive and has shown up a few cars which simply were not expecting. There are very few on the road so its a little surprise to people when they hear the charger wind up!

However, day to day driving isn't a drag race (well, assuming you don't participate in a little bit of traffic light GP!)

The wife drives the Micra around town and is great, returning 45mpg. The QQ struggles with town driving despite the engine size. Its to big of a car and too small of an engine with not enough low down grunt. Around 35mpg average for similar driving in the QQ.

However, start adding passengers to the Micra and it starts to struggle, not much but noticeable. By its nature, the 3 pot does not have a huge amount of torque available and you need to wind up the engine a bit more to get it going. Saying that, it's much better at handling this than the N/A version which is completely gutless to the point you could loose speed on a hill where as the DIG-S would at least maintain it (mix the NA with the CVT and its almost lethal, very very lethargic!)! The 1.2 DIG-T engine in the QQ however feels as though it has more umph behind it. It does not seem to get itself into trouble as quickly as the DIG-S does if that makes sense. Probably because the turbo is spitting out more boost than the supercharger does and the extra cylinder.

Now, sticking the 1.2 DIG-S in the Note, IMHO its a mistake. I had the 2008 (I think!) MK1 Note which had the 1.4 4 cyl engine. That wasn't the fastest car in the world and started to struggle with load, but mostly it was reasonable. I dare say that the DIG-S engine with its lower torque from the 3cyl engine will make it worse, not better.

As per original thread, driving a turbo engine requires a different driving style, or expectation of power. I have had an Almera N15 with the GA14DE engine and despite its inherent problems with weak gearboxes, and some weak bolts on the bottom end, it was a strong engine power wise that you could really throw it at all sorts. It had reasonable low down grunt and was able to push the Almera, which is similar in size/weight to the Note with reasonable pace. Now, jump into a car with a turbo engine and you need to wind the engine up a bit to get the power out of it and appreciate that it takes a moment for the turbo to kick in.
jet
Posts: 69
Joined: Mon Apr 06, 2015 7:48 am

Post by jet »

Thanks a lot, Splank! That was some valuable and interesting information.

Coming from a 1.4 N15 too, I was initially looking at the new (back then) Note. Tried the 1.2 N/A and it was tragedy, both in terms of sound and response. Not many 1.2 DIG-S here either, and with their price that's understandable.

The N15 was a really strong car (apart from the rust, apparently) - very easy and pleasant to drive, short and long journeys alike. The GA14DE is one of the most refined and flexible engines I have ever driven, and I still miss mine. Had 200 000 miles on the clock and was much quiter then a new 1.2 DIG (NA).
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Deleted User 759

Post by Deleted User 759 »

Yep, the reason I scrapped the N15 was mostly because it developed a rather large hole in the rear wheel arch and I was able to pull the seat mount anchor off the car with bearly any force! God forbid I was in a crash with a rear passenger! A welder mate of mine refused to go anywhere near it due to its proximity to the fuel filler kneck, and with a list of other serviceable thing needed to be done, I simply scrapped it just before its next MOT (after royally abusing the living daylights out of it for the last month whilst using the magical powers of gaffa tape to 'hide' the hole!). It only had around 70k on the clock but around 30 of those were tough. It was used as a work horse when we were doing up our horse. GA16DE was of the better of the 2 and had less issues (I had one in a P11 Primera), but yeah, the engine itself never let me down.

Price - My 9 month old, 8000 miles (at the time) 2012 Micra (Acenta trim) was around 8k + 2 services which considering their new value and what you get in return I thought was good value for money. Its been used and abused and has put up with a fair bit.

I am currently commuting in my QQ to work, however the wife is starting at my place next week so we are going to start commuting in the Micra, mostly because it is cheaper to run on stuff like tyres and slightly better fuelling.
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