A2 1.2Tdi compared to Lupo 3L

I've owned an A2 1.2Tdi from new for over 5 years (in the UK) and have been enormously impressed by it. I've now done about 82k miles (131k km) and average 95mpg including mostly city driving. The car achieved an amazing 120.2mpg (2.35l/100km) on a very careful measured run over about 170 miles.
I was so impressed that last year I went to Germany to buy a Lupo 3L for my wife to drive. I found one with only 15000 miles on the clock (genuine I believe).
However, the Lupo struggles to better 80mpg (3.6l/100km) and loses speed on hills that the Audi would fly up easily. The problem seems to be the power output of the engine which seems much lower than the Audi. The Lupo has to drop down a gear (or two) to climb hills that the A2 does in 5th.
The Lupo should be 20kg lighter than the A2 - so it's not weight. It has ordinary tyres on instead of the Bridgestone low resistance tyres but can this make such a difference?
Has anyone got any ideas why this difference exists?
 
Same with the petrol. The cw ist not so good as on the A2 and there must be something different in the geometry of the wheels/ front axle that it does not bring the same power on the road as the A2. (see technicle data sheet for the 1,4 petrol Audi A2 and Lupo...)
But I don't know. The normal Lupo is heavyer than an A2. But the 3l is different, I don't know exactly.
 
Andy,

We have two Lupo 3L's and an A2 1.2Tdi. I have the same problem in reverse - I cannot get the A2 to match the Lupo's consumption! However the A2 is fitted with wider than standard tyres, which probably accounts for some of the difference. How old is your 3L? Umfortunately they are easy to 'clock', simply by changing the instrument unit - this is also true of an A2 incidentally.

Have you done the simple things like changing the air filter? I had a similar problem with a 3L just after it had been serviced by VW. I had specifically asked them to change the air filter at the service because I had noticed from the service history that it had never been changed. Guess what, they hadn't changed it! When it was changed, it was just like a new car! At 15,000m, yours shouldn't need changing though, if it is genuine.

Tyres may also be a factor. The best for the car are Bridgestone B381's but Bridgestone, in their wisdom, have just stopped making them for the 3L.

RAB
 
RAB
Thanks for that.
I had a feeling that the tyres might be the problem. My Lupo has wide tyres and my A2 has the B381's. At least it did until today. I've just found out that there are no B381's in the UK and had to fit two other tyres. Do you know for sure that Bridgestone have discontinued them for good?
Presumably, I can test the air filter by removing it and seing if that makes a difference. I'll try it tomorrow (it's 10.30pm now).
Cheers.
Andy
 
Hi Andy
I would not run the engine without an air filter element fitted. The housing may have a lot of grit / dust stuck on the inner surfaces which could get sucked into the engine. Even if you managed to get it perfectly clean then dirt could still be sucked in on your road test. (A static test would be a bit pointless on a turbo car as max airflow is only achieved under full load / boost)

Cheers Spike
 
Andy,

Air filters are readily available from Halfords or VW - same as 1.4Tdi and only about £6 from the former. You can tell just by looking at it whether it needs changing. You have to drop the undertray though, which is a pain as the 3L is so low and you cannot use axle stands.

According to their website, B381's are still available for the A2 1.2, in theory anyway! There are only about three suppliers for this size which may explain why Bridestone still make them. In 2001 when I bought my 3L, Bridgestone were the only supplier for the 3L tyre - now there are literally dozens of suppliers, well almost! They have definitely stopped making them for the 3L.

I have a novel solution for our problems - just swap A2's!

RAB
 
Last edited by a moderator:
Ok, ok everyone. I promise not to remove my air filter!
RAB, good idea but wouldn't this mean I had a bad A2 as well as a bad Lupo??? Ermmmm. I'll let you know.
I've asked my friendly tyre supplier to get 10 B381's for me if he can locate them anywhere. I'm not holding my breath.
Andy
 
RAB, good idea but wouldn't this mean I had a bad A2 as well as a bad Lupo??? Ermmmm. I'll let you know.

Yeah, sort of, I thought you'd spot that!!!!!!!!

You may find old stock of B381's for the Lupo but B381's for the A2 are still in production, at least in theory. To be honest, I'm not sure that tyres are THAT important. I was on holiday in France once and had to fit Continentals to the front because Bridgestones were not available. On a plot of fuel consumption vs. kilometrage, I cannot detect when they were fitted. It is nothing like 5mpg difference, as some people report.
 
Last edited by a moderator:
Hi,
I apologize to resurrect such an old post, but the title fit perfectly my question!

More exactly, what are the exact common parts between LUPO 3L and A2 1.2 TDI?
Engine, gearbox and wheels, it's obvious, but what about brakes or front/rear axle?

Also, I could not find any press-release or book that details what is specific to the A2 1.2TDI compare to normal A2.
Does anyone know where I can find these informations? Is there a book about the A2 "3L"?
I understood the rear bench is specific to be lighter (only the monobloc one?) and the tank is smaller (does this matter) but i found very difficult to find more details

At least for the Lupo 3L there is a "Self-Study Programme" N°216 & N°218 that details all the 150 KG saved compare to a Lupo SDI
And it's amazing how much stuff are specific in the Lupo 3L, seats, thin glass, etc, even wall thicknesses of the
exhaust pipes have been reduced...

So is it possible that the A2 1.4 petrol weight 895 KG; the 1.4 TDI 990 KG but the 1.2 TDI 930 KG?
So the saving is just 60 KG here? (the 1.2 aluminium engine and the magnesium gearbox -and wheels- might be that lighter to the 1.4 TDI... )
Yet, it's 35 KG heavier than a 4 pot petrol A2?

My idea is to increase the efficiency of an A2 using the specifics parts design for the 1.2TDI, and preferably out of an old LUPO 3L (as I own a broken one)

And I would buy the parts for the aerodynamic stuff,
what is different, except that the body (the wheel arch) are narrower?

My dream would be a 1.4 petrol A2 with the narrow body and all the light parts of the A2 1.2TDI to reach the 60 MPG,
without the reliable issue of the 3L gearboxes, neither the noise of a diesel...

thanks a lot for your answers
francois
 
Last edited:
Hi Francois

Try this article for starters: A2 1.2L engineering

View attachment A2 1.2L engineering.pdf
It's from European Automotive Design May 2000. I cannot find it on-line so have uploaded it.

and see this diagram A2 1.2 TDI Features Differences
A2 1.2 TDI Features Differences.jpg

Key features for a lower cd:
- reduced wheel arch width
- narrow tyres (and maybe design/materials?)
- aero wheel trims
- blanked off front air intake
- under body smoothing
- aero wiper
- size, shape and position of rear spoiler
Total CD reduction from 0.28 to 0.25

Key features to reduce weight:
- aluminium suspension components including lightweight axle
- alloy brake drums and callipers
- lighter seats
- Lupo engine
- reduced body equipment (unspecified)
- reduced trim (unspecified)
- Fleece wheelhouse liners
- thinner front and rear glass screens
- smaller fuel tank
Total saving 165 kg

Key features to reduce inefficient driving
- auto gearbox with ECO mode and start/stop
 
If you want to modify the petrol A2 make it an EV. Plenty of others doing the same in EU.

But 1.2 TDI is a very special car - much more involved and expensive to make your own - just buy a real one. The gearboxes are very good (mine has done over 213000 miles now) it is the hydraulic and electrical side of the gear change that can give problems. But looked after no real issues.

Diesel by design. It is actually quieter than the new BMW i3 electric car over 50 mph! And the low speed thrum is characterful not intrusive - especially with such a good start stop system.

The B381 tyres and Winter 145/80R14s are back in production again.
 
Hi guys, i have found used some nice Ancora STP Lupo Gti rims and thought about buying and fitting them to my Lupo 3L, which now has oem magnesium wheels fitted. They are 15, 7j, et 40, and i think the right tyres would be 195/45/15. Would I noticably compromise the mpg and acceleration of the car by doing so?
 
Very slightly smaller (-1mm) OD but ride comfort?

RAB

Well, i havent really thought about ride comfort, just mpg and acceleration. But now that you have brought it up, and having taken into account the fact that the car has no power steering as well, i guess the best thing to do would be to leave all as it is now...
 
I thought that it would be nice to resurrect this thread... as I've just got Andy Fisher's old A2 3L back on the road and it's now my daily driver.

After a failure of the gearbox ECU (possibly caused by some of the hydraulic components / solenoids etc - I changed the lot!) I was able to get the car up and running and MOTd.

I've driven my Lupo 3L every day for 2 years now and driving the A2 3L shows some interesting differences.

1) Despite having covered more miles, the Lupo suspension is in better condition. The A2 shock absorbers (I think) have had it. I am looking at replacements. Despite this, the A2 ride is better on the normal roads but it does bottom out easily on speed humps etc where as the Lupo doesn't and is more controlled.

2) As the A2 has taller tyres, the acceleration is noticeably slower (well to me anyway). Maybe the performance will improve after a timing belt and service.

3) The gear change is quicker on the A2 than the Lupo. I wasn't sure at first but now I am certain. The A2 uses a different ECU and shift pattern inside the car and both use the same hydraulic parts but I think that the programming within the ECU is different to speed up the gear shifts.This is something that I have never read about. Has anyone else found this?

4) The A2 is quieter inside... but not by much. I guess it must be more insulated and it is a very different vehicle.

5) Stop - Start seems to be a bit more sporadic on the A2 than the Lupo. When it is cold... it works but once you have driven a short distance, sometimes it works and sometimes it doesn't. I need to read up on the A2 3L pre-requisites for it functioning.

6) Cabin heating. The Lupo is quicker to get some warmth through to the occupants. The A2 seems to take an age to get any warmth through to you... I presume that it has the same electric elements inside the heater box? My A2 3L has climate control with Air con.

7) Fuel tank size... why oh why did Audi put a 21 litre fuel tank in it?? Using the extra breather tank in the Lupo 3L, you can get more than twice that amount of fuel into the Lupo! Maybe I'll look at fitting a normal A2 fuel tank. Anyone else done this?

That's all for now ;)

MG
 
The A2 1.2 TDi is much lower weight than the 1.4 petrol car - especially in D4 format. The 1.2 has thinner front windscreen, narrower wheel arches, aluminium subframe (Petrol has steel), aluminium lower wishbones (not steel), the 1191cc engine weighs around 100kg (much lighter than even the AUA). The wheels are magnesium, the rear drums are aluminium, the insulation is reduced, all unnecessary trim is removed (even less coat hangers!).

The D3 has power steering and removable rear seats the D4 is manual with fixed lightweight rear bench. More like 855kg and lower CdA than the Lupo 3L.

D3 also came with option of a larger fuel tank later on - I think it was 34l.

Never had an issue with just 21l tank myself - over 300 miles even in winter with winter tyres is very do'able.

Noise: Again aerodynamically the A2 is much quieter and this also helps the freewheel mode from higher speeds.

http://www.autointell.com/News-2001/May-2001/May-2001-4/May-23-01-p8.htm
 
Last edited:
The Lupo suspension seems far superior to me, new or old. A blindfolded passenger would think that the Lupo was the more expensive car.

Never noticed any difference in gear change speed. A slightly slower change may mean your clutch actuator pot is on the way out.

The A2 is quieter at speed but at rest, the Lupo is far quieter. That was my wife's first comment when we went to collect it in Germany!

Stop/start can be affected by many factors: ambient temperature, coolant temperature, state of battery etc. etc., but some are under your control.

The Lupo and A2 have the same electrical cabin heater, so there shouldn't be any difference. Pressing ECON on the A2 turns it off, as does turning the heater control on the Lupo to lower than about 1 o'clock.

My 1.2 has the 34L tank. It was a cost-free option! Not sure why anybody would have chosen the 21L, unless it affected whether it was D3 or D4.

RAB
 
Back
Top