MPG, petrol

[allonym]

We (myself and the good lady) have been test driving potential new cars. Obviously there's lots to consider but I thought I'd post the results of out very unscientific tests of fuel economy. The basic idea is we pick up the car from the local dealer (we live in Norwich) drive home (which is on the West side of the city) and then drive westwards along the A11 to Barton Mills. This is a journey of just under 39 miles. 2 miles of low speed driving, 27 miles of 70 mph dual carriageway (4 roundabouts), 9 miles of single carriageway (2-3 miles (rough estimate) of which is 40 mph and the rest 60 mph). The journeys below were all weekend afternoons with essentially no delays due to traffic.This is what we got (numbers all from the car info systems):

BMW 116i Sport 41.7 mpg
Audi A3 1.4 122 TFSI SE 46.9 mpg
VW Golf 1.4 140 TSI ACT GT 43.3 mpg

The real interest here I think is the comparison between the A3 and the Golf. Obviously there are a many variables that can affect fuel economy. The temperature was similar on both days (-1 to +1), the the driver was the same (me), load the same (myself and GL), speed similar (basically the legal limit all the way), but somethings were different, it was windier and a bit wetter for the Golf and the Golf had done fewer miles (500 vs 3,500 for the A3), and somethings we simply don't know about (tyres, including pressures), fuel type, wheels size (17s on the Golf, forgot to check the A3), differences between the on-board mpg reporting on the two cars, etc, etc.

Because of all the variables (not least they're different cars, albeit on the same platform) I'm not drawing any firm conclusions. Even so, I have say after the pretty good mpg of the A3, I'm a bit disappointed with the Golf with its cylinder deactivation 1.4 and the promise of more power and better fuel efficiency. Thoughts?

 

[mjcourtney]

Have to say, i've driven the Golf 1.4 ACT and the A3 1.4TFSI (which I have subsequently ordered), and the Golf ACT felt nowhere near as refined or smooth as the A3. The transition when the cylinders cut-in/out was noticeable, and it didn't feel as nippy as the more traditional A3 engine - despite having extra BHP on paper. As for MPG - can't comment as haven't driven either of them for long enough, but i'm hopeful of getting at least 40mpg out of the A3.

 

[JudderMan]

The Golf will probably get better mpg with more miles under its belt. It'll be due an oil change soon with just 500 miles on the clock and should 'free up' a bit if it had 3500 miles like the A3. That said, we're on an Audi forum so I say go with the A3. Four circles are better than two letters

 

[allonym]

mjcourtney, We thought both were very smooth and refined and would be happy with either in those respects.

JudderMan, Leaning towards the A3 at the moment as both the GL and I prefer the cabin over the Golf and I prefer the exterior looks too (and it will really be my car). Which engine is the main question at the moment. 1.4 122, wait for the 1.4 140 or the 1.8?

 

[JudderMan]

I'd go with the middle ground 1.4 140bhp as it's cheaper tax compared to the 1.8 and has probably enough power to haul the 1200-1300kgs of car.

 

[allonym]

Yeah, I think that's the sensible move. Also, insurance will be a bit more for the 1.8, fuel costs and CO2 emissions will be higher, and according to another thread here availability of a manual version seems to be in doubt anyway.

 

[dieseldoug]

Look at the OTR prices of the same spec car 1.4/1.8 petrol against the 2.0 diesel, right away you are saving on the price of the car, saving on fuel regarding MPG, diesel emissions are less so the tax will be cheaper. Forget about DPF filter you would have to be running 1 mile each way to get this clogg and leave idleing basically Diesel is cost affective.
AH now I hear you saying but diesel is more expensive, well work out the average miles you do divided miles to gallon then by the current cost per liter again buy a diesel car, if your still not sure and your car at present is petrol stick with petrol simple.

 

[h5djr]

Reading an article in this week's Auto Express they say they on average you need to do around 15,000 miles a year to make diesel more economical than petrol in the UK. With my existing 2.0TDI -170 I do around 14-15,000 miles a year, but around 3,000 of those miles are done in Europe where diesel is much cheaper per litre than petrol. The other factor for me when I change will be is it available with the 6-speed wet-clutch s-tronic like my existing car.

 

[allonym]

Lots of factors play into whether a diesel is cheaper overall, including how long you own the car and future fuel prices (which of course are hard to guess). I do like the idea of lower running costs (even if they don't fully offset purchase price differences) and the idea of lower CO2 emissions, but DPF is the worry. Currently I average 8-10k miles per year but some weeks it's only 50ish miles of short journeys, others it's 500 or more with much longer trips. I've read enough about DPF problems for the 50 mile weeks to give me DPF anxiety!

 

[dieseldoug]

are you worried about punctures also!! DPF issues run the car correctly and you will not have any, more chance having a puncture! stay with the correct fuel as required in the handbook, use the correct oil and service as per OEM and not Joe Bloggs.
Someone needs to do there maths regarding purchase and operational costs Diesel is a win win. but if you are a Petrol head stay with it some people like the thrill of petrol engines.

 

[Sootchucker]

I have to agree with Dieseldoug over the DPF thing. My Rocco TDI is fitted with a DPF, and I too was a little woried when I first got it. However nearly 2 years later, I've not had a single issue with it, (not even had the regen light on once). Not bad when you consider that my journey to work is only 10 miles through a town centre and busy inner city A roads. During the winter it never gets fully hot by the time I get to work, (oil at about 70°C when I arrive), and yet I still get no issues.

So long as you are sensible and don't use a diesel for prolonged 1 mile hops (dropping the kids off at school only for instance), then I don't think you will have an issue.

 

[allonym]

Not sure I should take advice from people called dieseldoug and Sootchucker

Here's what the AA have to say about DPFs:

http://www.theaa.com/motoring_advice/fuels-and-environment/diesel-particulate-filters.html

And Honest John (albeit talking about a Volvo)

"The best advice I can give is never do more than three short runs from cold starts without then taking the car on a run of at least 20 miles."

http://www.honestjohn.co.uk/askhj/answer/38989/will-my-new-warranty-cover-the-dpf-

Lots more similar advice on that site.

I've never owned a diesel and not sure I've even driven one with a DPF and I do appreciate your advice chaps. I think though that the peace of mind of being DPFless is worth it for me.

 

[h5djr]

I have owned three A3s with DPFs. All 2.0TDIs, two 170s and one 140. I am retired and no longer do a regular journey to work every day. Some of my journeys are only a few files but I do a regular 140 mile trip to see my mother at least once a month. I also take my A3s on holiday to Germany and Austria with trips around 3000 miles. I have never had a problem with any of the DPFs and have never seen the re-gen light. Don't let tales of problems with DPFs put you off. If you like a model with a diesel engine, go for it.

If your thinking of s-tronic, the diesels all get the better 6-speed wet clutch version because the 7-speed dry-clutch version cannot handle the extra torque of the diesel engine. I owned 19 petrol engined cars including four petrol engined A3s and have been more than happy with my four 2.0TDIs.

 

[lgooch]

We (myself and the good lady) have been test driving potential new cars. Obviously there's lots to consider but I thought I'd post the results of out very unscientific tests of fuel economy. The basic idea is we pick up the car from the local dealer (we live in Norwich) drive home (which is on the West side of the city) and then drive westwards along the A11 to Barton Mills. This is a journey of just under 39 miles. 2 miles of low speed driving, 27 miles of 70 mph dual carriageway (4 roundabouts), 9 miles of single carriageway (2-3 miles (rough estimate) of which is 40 mph and the rest 60 mph). The journeys below were all weekend afternoons with essentially no delays due to traffic.This is what we got (numbers all from the car info systems):

BMW 116i Sport 41.7 mpg
Audi A3 1.4 122 TFSI SE 46.9 mpg
VW Golf 1.4 140 TSI ACT GT 43.3 mpg

The real interest here I think is the comparison between the A3 and the Golf. Obviously there are a many variables that can affect fuel economy. The temperature was similar on both days (-1 to +1), the the driver was the same (me), load the same (myself and GL), speed similar (basically the legal limit all the way), but somethings were different, it was windier and a bit wetter for the Golf and the Golf had done fewer miles (500 vs 3,500 for the A3), and somethings we simply don't know about (tyres, including pressures), fuel type, wheels size (17s on the Golf, forgot to check the A3), differences between the on-board mpg reporting on the two cars, etc, etc.

Because of all the variables (not least they're different cars, albeit on the same platform) I'm not drawing any firm conclusions. Even so, I have say after the pretty good mpg of the A3, I'm a bit disappointed with the Golf with its cylinder deactivation 1.4 and the promise of more power and better fuel efficiency. Thoughts?

Driving in the rain makes a huge difference. More drag and therefore more energy required to maintain a constant speed. I notice a huge difference doing a 7 hour stint to Aberdeen when it's raining

 

[dieseldoug]

Allonym,
You kind of answered your own question there so buy yourself a petrol!!
I have at home 2 Audi's, 1 Golf, and 1 Seat all diesels never seen a DPF come on yet. I also have a petrol 1.2 Polo for my daughter which has just passed her test, in years this will be replace with Diesel also.
Take the advice of the AA and honest John!!
As for Dieseldoug, I work on diesel engines of many horse power and usually calculate fuel burn in ton's for over 30 years hence my user name...

 

[allonym]

I have owned three A3s with DPFs. All 2.0TDIs, two 170s and one 140. I am retired and no longer do a regular journey to work every day. Some of my journeys are only a few files but I do a regular 140 mile trip to see my mother at least once a month. I also take my A3s on holiday to Germany and Austria with trips around 3000 miles. I have never had a problem with any of the DPFs and have never seen the re-gen light. Don't let tales of problems with DPFs put you off. If you like a model with a diesel engine, go for it.

Your usage sounds quite like mine, even down to visiting mum and long holiday drives in Europe. We drove to Corsica a couple of years ago and have thought about Sardinia, although I really fancy a trip through Scandinavia towards the Article Circle, may be even to the Arctic Circle . I am reassured a bit by your post and will think harder about a diesel.

If your thinking of s-tronic, the diesels all get the better 6-speed wet clutch version because the 7-speed dry-clutch version cannot handle the extra torque of the diesel engine. I owned 19 petrol engined cars including four petrol engined A3s and have been more than happy with my four 2.0TDIs.

Thinking manual really.

 

[allonym]

Allonym,
You kind of answered your own question there so buy yourself a petrol!!
I have at home 2 Audi's, 1 Golf, and 1 Seat all diesels never seen a DPF come on yet. I also have a petrol 1.2 Polo for my daughter which has just passed her test, in years this will be replace with Diesel also.
Take the advice of the AA and honest John!!
As for Dieseldoug, I work on diesel engines of many horse power and usually calculate fuel burn in ton's for over 30 years hence my user name...

The point of this thread really was to discuss the 1.4 COD, a petrol that supposedly has getting on for diesel like efficiency but you have all got me thinking!

 

[paul8852]

Me too allonym, was going to hold out till May to order my 1.4 Tfsi S Line Sportback 140bhp ACT but having heard a number of slight negatives out there regarding this engine, especially in the Golf and not just on this forum, I'm tempted to go for the standard 1.4 Tfsi 122bhp which I must admit was a dream to drive last week, albeit, in SE trim, at least delivery will tie in nicely with original order date!! Decisions decisions...

 

[allonym]

Agree about the 1.4 122. It's a lovely drive.