78.8mpg. Audi A2 2005 1.4tdi

murdo

Admin Team
Re: the S4, I was working on the launch event travelling to dealers to train them on the car and half way through the event when Audi worked out how much fuel we were using they decided to give us a fixed fuel allowance rather than a fuel card. So it became profitable to save fuel as they assumed 20mpg (we had been averaging 12mpg) so 30mpg made £££, even they were surprised it was possible lol.
I'll eat my words. This makes perfect sense!
 

Ricardo

A2OC Donor
Plus I got bored scaring BMWs. At the time the S4 wasn't officially available and there were only 8 in the country which we were using to visit dealers. I remember a 330CI on the M1 that put his foot down to get away from me in the fast lane. I just sat there waiting for him to pull over as the speed crept up. He bottled in the end, didn't know there was a 4.2 litre V8 behind him :)
 

Artsi_L

Member
Greetings all. First post ever.

I've had the A2 1.4TDI for 6 days now. I'm a long time owner of a 90hp 1.9TDI Passat, so I'm familiar with diesels.

My ex-Passat was modded, custom turbo, single mass flywheel, heavy duty clutch, 11mm pump head and matching high lift cam plate, diy free flow exhaust, high flow injectors, custom made chip, etc...
My TQ was almost twice the original and a shy over double the HP of the original. Fun to drive.

On numerous occasions I recorded highway mileage of 4,7 liters/100km fuel consumption (imperial gallons 60mpg). I consider that a very good accomplishment from a 1420kg car with two adults, two teenagers and weekend baggage in the trunk. Speeds were from 52mph to 65mph.

I've just finished a 371km (230 ml) journey with my 1.4TDI A2. I set to drive slow and see what 1.4TDI can do. I kept a steady and boring 85km/h (52-55mph) constant speed.
To my disappointment I got 4,46 liters/100km (i.e. 63mpg). I was expecting more.

I have 16" wheels with very uncomfortable 45 series 195 rubber on it, inflated to about 42psi. I guess rolling resistance should be quite alright since low profile tyre will not allow much tyre flex at 42psi.
These wheels give me gearing to have 2050rpm to 2100rpm revs at above mentioned boring speeds.

Surely filling the tank before half way mark leaves room for error in refilling the tank. Does one stop filling the tank the first instant the fuel pistol goes click as the back splashes cut off the fuelling, or does one keep on going a few clicks more - which will bring mpg figures down as more fuel can be crammed into the tank.

This error margin will have smallest impact when tank is filled when it is totally empty. I admit filling my tank up at before half way was up can potentially skew my figures.

However let's stick with my 63mpg for a while - is this normal consumption for a gas pedal feathered 1.4TDI?

[edit: corrected the mpg to 63]
 
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johnmed

A2OC Donor
Greetings all. First post ever.

I've had the A2 1.4TDI for 6 days now. I'm a long time owner of a 90hp 1.9TDI Passat, so I'm familiar with diesels.

My ex-Passat was modded, custom turbo, single mass flywheel, heavy duty clutch, 11mm pump head and matching high lift cam plate, diy free flow exhaust, high flow injectors, custom made chip, etc...
My TQ was almost twice the original and a shy over double the HP of the original. Fun to drive.

On numerous occasions I recorded highway mileage of 4,7 liters/100km fuel consumption (imperial gallons 60mpg). I consider that a very good accomplishment from a 1420kg car with two adults, two teenagers and weekend baggage in the trunk. Speeds were from 52mph to 65mph.

I've just finished a 371km (230 ml) journey with my 1.4TDI A2. I set to drive slow and see what 1.4TDI can do. I kept a steady and boring 85km/h (52-55mph) constant speed.
To my disappointment I got 4,46 liters/100km (i.e. 63mpg). I was expecting more.

I have 16" wheels with very uncomfortable 45 series 195 rubber on it, inflated to about 42psi. I guess rolling resistance should be quite alright since low profile tyre will not allow much tyre flex at 42psi.
These wheels give me gearing to have 2050rpm to 2100rpm revs at above mentioned boring speeds.

Surely filling the tank before half way mark leaves room for error in refilling the tank. Does one stop filling the tank the first instant the fuel pistol goes click as the back splashes cut off the fuelling, or does one keep on going a few clicks more - which will bring mpg figures down as more fuel can be crammed into the tank.

This error margin will have smallest impact when tank is filled when it is totally empty. I admit filling my tank up at before half way was up can potentially skew my figures.

However let's stick with my 60mpg for a while - is this normal consumption for a gas pedal feathered 1.4TDI?
That's lower than I would expect. I drove from Cheshire to Essex on Saturday. I did sit behind the odd lorry, but only for maybe 1/5 of the journey tops. This was the highest average MPG DIS showed:


And door to door I think I achieved 78.8 or 9 MPG. At a constant 56 MPH. I pulsed and glided on hills.

My return journey was late at night, and I stuck at 70 MPH, and with two M'way closures and horrific detours I still achieved 60 MPG, again on DIS (I haven't got the inclination to work out the exact MPG these days).

P.S. I think I read a post by Tom/Timmus saying the A2 roughly at 70mph returns 60mpg, at 60mph 70mpg...
 
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dan_b

A2OC Donor
Welcome. I'd say that's a reasonable base MPG - many on here would kill to get 60MPG, but there are some who are higher and many who are lower. Give it a bit of time and see if it settles before we start wondering if there are any technical issues like sticky thermostats.

One thing that is easy to say though is that on the A2, wheel size and weight has a big impact on MPG. I always see a drop in MPG going from my very skinny 155/65/15 winter steel wheels to my 195/50/16 summer alloys. When I had 17s it was impossible to get much over 53MPG. On the 15s, I regularly get 70MPG, and 60ish on my 16s.

The A2 is also somewhat under-geared for very efficient motorway cruising - several on here (myself included) have done gearbox mods to try and improve this, ranging from altering the 5th gear ratios to adding in a complete extra 6th gear.

There are various other little aero mods you can bolt on - taking parts from the 3L-version of the A2 (3x sets of spoilers and panels that all go underneath the car to smooth airflow).
 

Gonzo

A2OC Donor
And I'd take DIS readings with a pinch of salt. My A6 is about 10% optimistic compared to brimming.

I recently changed down to 15" 195/55 tyres and did two long journeys going as fast as the traffic would allow, often cruising at 80-85 mph. The car averaged well over 60 for both - I think one was 64mpg over 300 miles including some town. Without even trying. And measured brim to brim.

I'm sure you'll get more over time!
 

Artsi_L

Member
Hello

My second full tank had less city driving, hence it gave me 71mpg, and the latest extra urban highway trip full tank was 74mpg. I am unable to drive any slower than about 53mph, otherwise I'm blocking the flow of traffic. I hardly ever overtook anybody while "hypermiling".

I'm sure 195 wide tyres (like mine) are not a real hypermiling choice (195/45-R16 to be precise). I am looking to replace 195 wide shoes most likely with a set of 165/80-15. That'll offer me around 10% longer gearing compared to present rubber.
Accomplished hypermilers seem to prefer 145/80-14 Bridgestone B381. Maybe that'll be my next year's option to go with.

Gotta have this car reprogrammed at some stage. The word is that'll bump up mpg about 10%. In MPG I'd love to get into low 80's to high 80's club.
 

AudA2Numpty

A2OC Donor
I love how sad we all are ... talking excitedly about smaller wheels and narrower tyres ... free wheeling to junctions ... love it :) If I'm planning a long journey I take the rear seats out :D

That is genius. I'm trying that next time I go up to Scotland on my own.
 

Gonzo

A2OC Donor
Well, I've not really paid much attention to the mpg wars as our Tdi spends most time in an urban environment and gives 45-50mpg week in week out. I know it's 45 cos that's 10 miles per litre.

However, we've just done about 500 miles across 2 days.

370 miles until the buzzer got me 59.6mpg. That's 200 miles of M'way at 80mph where possible, 70 miles of Yorkshire up and down A roads and the rest the urban crawl.

However, the 160 miles since filling up on the M1, at around 75mph have given a faintly astonishing 77.2 mpg, including 5 miles home off the motorway. Without trying. And with lights, air con and wipers.

Genius. I can finally see how some can get over 80, albeit with a level of, ahem, "focus" that I suspect is beyond me.
 

MikeMarsUK

A2OC Donor
... However, the 160 miles since filling up on the M1, at around 75mph have given a faintly astonishing 77.2 mpg, including 5 miles home off the motorway. Without trying. And with lights, air con and wipers.

Genius. I can finally see how some can get over 80, albeit with a level of, ahem, "focus" that I suspect is beyond me.
Well, step number 1 would be to drop your motorway cruising speed down as much as reasonable - aerodynamic drag is the biggest MPG factor on the motorway. :D On a single long trip that'd push you into the upper-80s region on it's own.
 

dan_b

A2OC Donor
I'm back under 60MPG again - I'm suspecting my handbrake/rear drums might be binding. Niggles.
 

Artsi_L

Member
Hello

I've made an Excel chart on my fuel consumption. It has a table with consumption numbers in L/100km, UK and US MPG.

These are driven in summer/autumn. Tyres 175/65-R15 all season traction tyres (i.e. okay for snow and ice), definately not low rolling resistance tyres. Inflated to 47psi, which helps to gain back the rolling ability.

These are purely highway cruising fuel consumption numbers at steady speed, virtually never overtaking anybody. This is also a solo effort, not driving behind a lorry or truck. When I've been behind a truck, I've kept a healthy distance of about 30-40 meters to the truck.

--

I would have assumed that increasing the speed from 90kmh to 100kmh would be some percentage increase, and increasing from 100kmh to 110kmh would be even greater increase in percentage as wind drag starts to play more role. According to my experience, it is not a steady increase of fuel consumption as the speed increases. There are bumps.

On my chart increasing the speed from 100kmh to 110kmh has the smallest percentage increase in fuel consumption. Go figure. I don't understand this.


my mpg table.pngmy mpg chart.jpg
 

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MikeMarsUK

A2OC Donor
... I would have assumed that increasing the speed from 90kmh to 100kmh would be some percentage increase, and increasing from 100kmh to 110kmh would be even greater increase in percentage as wind drag starts to play more role. According to my experience, it is not a steady increase of fuel consumption as the speed increases. There are bumps. ...
Nice chart.

This is the rule of thumb I like to quote ... UK MPG = 130 - miles/hour

(only for typical motorway speeds, not particularly accurate, assumes on the flat / no wind / engine up to temp / dry / etc).



The wind drag is the square of the speed, i.e., if you double your speed you quadruple the drag. It starts to be the dominant factor at roughly 50mph. However, the engine efficiency map is somewhat complicated and this is also a factor.

The ALH map is probably reasonably similar to ours.

http://ecomodder.com/wiki/index.php...aps#Volkswagen_Jetta_TDI_1.9L_ALH_1999.5-2003
On this map, the lower the 'contour line' figure, the better - 197 being the best fuel consumption on that graph). If you are cruising steadily on the motorway, you're not using many HP - lets say 20hp for example. So follow the blue 20hp line until you reach the RPM for your gear, find the nearest contour line, and that gives you a rough indication of the engine efficiency. Higher gears are normally more efficient due to the lower RPM until you get to the very low RPM areas on the graph.

So picking 20hp, 60mph as an example, lets say that I am in 5th and doing roughly 2000rpm. That's about 240 on the chart. I then drop it into 6th gear, 1750rpm or so, and that's 230 on the chart. So maybe 4% better efficiency in that example for the same road speed.
 
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Artsi_L

Member
New personal record.

Trip stats.

75hp 1.4 TDI, not reprogrammed. Box stock standard car.

Started recording as I was at my cruising speed on the motorway, and engine warmed up (i.e. fuel consumption not measured to bring the car up to cruising speed).

Cruising at steady 80km/h speed (i.e. 49MPH).

Solo effort, I was not trailing larger vehicles.

Tyres; winter season non-studded CONTINENTAL friction tyres, 175/65-15, inflated to 3,2bar (47PSI). The tyres were on their last stretch, contact surface almost completely worn off, which helped to achieve minimum tyre flex on contact layer, hence improving tyre rolling ability.

Cargo; me and Mrs, our dog, and weekend's worth of stuff in the car plus stereo speakers we picked up on the way (all totalling maybe about 205kg/450 lbs).

Measured distance, 100,4km, 62,4miles.

I was at 89.9mpg as I let the car to roll free onto the off ramp I had to take. During that quarter of a mile free rolling, my overall mpg broke into the 90's.

UK MPG 90,2
3,1 L/100km

I have spent 5 months dialling in Android (Torque) software to have fuel consumption measurements as close to reality as I am capable. I am within 0,1 liters/100km. However gallons to mile is more sensitive measurement table. I can have MPG to change several digits while liters per 100 km remains the same, hence my real fuel consumption can be something in between 89mpg to 91 mpg.

Screenshot_2014-11-03-22-08-33.jpg
 

AudA2Numpty

A2OC Donor
As it turned out in 2016 I stupidly sold my original A2, bought a short range electric car, moved to Sweden but constantly found I needed the A2 for long distance driving as Sweden was sooo big.

So when we returned from Sweden I immediately went out a bought another A2. This one has an open sky roof but the rest of the car was in a terrible condition and still has a few issues to sort out.

Well the first fuel up was slightly disappointing, only 55mpg. Then the wife had a trip down to Woolacombe in Devon, by then the undertray had been taken off and broken, but I had managed to clean the car and pump up the tyres to 40psi. Her return trip resulted in a return of 61mpg, but I was not really expecting much as she is not an mpg fanatic like me.

Thankfully Tony from A2 cars was at hand and sorted a good portion of bigger issues to help us on our way, with a full service and other bits, including a new undertray and fixings for bits broken.

The next fuel up was an expectedly disappointing 56mpg. But the next was a bigger surprise at dismal 61mpg, though they were all short hops and I was doing everything I could to be good with fuel consumption it still was lower than I'd hoped. I then started to blame the extra weight of the Open Sky roof for the poor consumption until I remembered what Tony said when I had my first A2.

So I bought some Redex Diesel cleaner and topped up the tank, this resulted in an improvement, 69.85mpg from the first leg of a marathon trip to Bordeaux with the car loaded fully of suitcases, extra bags, our dog and myself of course.

While near Bordeaux Airport, I topped up and looked at the calculation on my smart phone, this resulted in a much more respectable 76mpg. This was driving at 55-65mph, with tyre pressures at 36psi, the outside temp was around 28 degrees and no aircon as the bloody Climate Control Unit keeps cutting out anyway. Very pleased with that. it could have been better than that but I was avoiding the Toll roads and must have seen more than 100 road-a-bouts on the smaller roads.

I know the next fuel up is going to be horrible as I picked up the wife and daughter from Bordeaux airport with the car fully loaded with bags and drove two hours at 130kmh on the toll road back to our final destination with the aircon flickering on and off as the outside air temp got up to 34 degrees.

Does anyone else think the redex has helped the massive improvement in mpg, in only two tanks worth?
 
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According to Fuelly I'm getting around 64mpg on my 1.4TDi, driving reasonably carefully; not bad on 220,000 miles. I did run some Wynns through it a couple of months ago and I do use a squirt of 2 stroke as well - the best I've seen is 70mpg on 2 successive fillups.

I'd be very wary about over inflating tyres - if you're involved in an accident where you've lost control that could be said to be a contributary factor (less rubber on the road) and your insurers could decline liability on your claim.
 

ROO3

Member
Hi all,

There are no mods on the car, though there is a pending cruise control fitting.

I don't have a DIS either, though I originally wanted one I think I don't really need it.
My car also doesn't have fog lights.

The only thing I have done is to turn off the air con.
I have 15" wheels which were set at the higher pressure as listed in the back of the diesel filler cover.

I'll be taking another long trip soon (without family and suitcases) and will see if I can crack the 80mpg mark by removing the rear seats.

As for driving style I am a believer in the clutch down technique while coming up to roundabouts, red traffic lights and stationery traffic all at slow speeds.
I suppose both of my high mpg top scores were possibly due to very big hilly journeys through the Cairngorms and Lakes?

I suppose this is a form of cheating as the car will be in idle for short spaces of time. When I wasn't trying this technique I was getting 65-68mpg.
Though it's interesting how much extra you can get by "coasting".

When the wife does the school run the best she got (though she couldn't give a crap about mpg) was 52-55mpg.
The other thing was that I added the redex diesel additive.

I do want to try a few aero mods though and maybe the 5th gear mod. But at the mo my car needs new rear suspension and a pending drive shaft replacement so this will be a dream for now.
What tyre pressures do you recommend?
Which fuel? Supermarket?
 
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