TDI vs FSI: fuel consumption

[THR]

Hi all,

I don't intend this to be a FSI vs. TDI/petrol vs. diesel discussion topic. I simply want to validate whether under my driving conditions, it was worthwhile purchasing a diesel over a petrol. As such, I would like to know the experience of others driving under similar driving conditions (as I will explain below). Any petrol Golf owners are welcome to contribute (as well as diesel).

We've had our Golf TDI DSG 2.0 (Comfortline) since February. In that time we've done approximately 3,500km (i.e. nothing). Average consumption in that time is 8.8l/100km. Admittedly we did break it in hard (i.e. babied for first 300km, accelerated quickly to 2,500rpm (once engine had warmed) until around 1000km, and harder after that). Did not start to use cruise control until 1,500km (and this is the first car I've had with cruise control - but I love it now).

Anyhow, we mostly do city (Sydney) driving - a lot of start/stop and very little, as yet, long distance (as per 3,500km in 5 months).

I'm wondering under similar driving conditions (99% city) and start/stop traffic, what petrol Golf owners are doing on average and to the tank?

We get about 700km to the tank and have noticed lately that it is being more efficient (perhaps I've been a bit more lightfooted on the accelerator).

Lastly, if anyone is wondering why you would pay $x,xxx more for a diesel when you don't drive sufficient KM's to produce the economy savings to warrant the additional $2,500, we just liked the feel of the diesel more. Economy was a consideration, but I love the torque, etc.

Welcome your input

[Preen59]

You'll find as it loosens up until around 10,000kms, you'll get progressively better fuel economy.

That's what i found with my TDI Caddy, and it seems to be the general consensus of opinion.

[h100vw]

It should improve overall but only doing sub 10000Ks a year you'll not recoup the extra money you have spent on the diesel engine for years.

In the UK they reckoned you needed to do 30000 miles a year to warrant the extra cost of the diesel.

Gavin

[brad]

5 days ago I took delivery of a Skoda 1.8TSI M6 - the same engine as the latest Audi A3; the bigger 2.0 version will come out in the Golf GTI later in the year.

I filled up with 98 last Sunday & the low fuel light came on today after 750km. It used 48L of fuel & I was more or less driving like I always do (I got bored with trying to run it in after about 70km).

That's 6.4L/100km but 90% of my driving is on Sydney motorways which this week have been reasonably free flowing at around 80-110kmh.

The 1.8T is a torquey little bugger (about the same as a 1.9TDI) but not as good as the 2.0TDI.

[THR]

^ Thanks for that. Good to know (totally different driving conditions, but that's good economy).

Appreciate that given the low KM's travelled, it'll take forever to recoup the cost - I am just wondering whether the economy, given the rising price of diesel, is farcical from the outset.

[brad]

^ Thanks for that. Good to know (totally different driving conditions, but that's good economy).

Appreciate that given the low KM's travelled, it'll take forever to recoup the cost - I am just wondering whether the economy, given the rising price of diesel, is farcical from the outset.

Possibly, but if you were really worried about economy & lived in the inner city then you would have Prius.

For me, the way the engine performed was the selling point. Fuel economy appears to be an added bonus.

[THR]

Agreed, economy wasn't the driver - but what I mean is, given the extra cost of diesel, is there actually *any* saving in such conditions.

[brad]

Agreed, economy wasn't the driver - but what I mean is, given the extra cost of diesel, is there actually *any* saving in such conditions.

My old Golf 2.0l 8 valve averaged 9.4L/100km when my missus was driving it from Hurstville to Ultimo every day. It wasn't nearly as fun as a diesel Golf.

My 2.5l Liberty auto was averaging 11.3L/100 driving Hurstville to the airport everyday. It was even less fun than the Golf.

so on a dollar:fun basis you are probably being quite economical.

[gregozedobe]

Trouble with looking at these sorts of figures are that you aren't ever comparing like for like. Different drivers, different driving styles, different driving conditions, different loads, different tyre pressures etc etc all have a big impact on fuel consumption.

Besides, it is a bit late now, just enjoy the torque of your TDI

[THR]

Indeed,

I think I have my answer... what's the point in quibbling over $10 or so a week

[The_Hawk]

Lets do some calculations. First some assumptions:

If fuel is $1.75/L
If diesel will give better fuel consumption by 5L/100 KM

So for every 100km you save 5L of fuel.
5 x $1.75 = $8.75 / 100km

At $2,500 more:
2,500/8.75 = 285.714 lots of 100km
= 28,571.4km before you break even.

Now consider if Diesel only gave 3L/100 km difference, that works out to be 47,619km before you break even.

The higher the fuel cost the quicker you will recoup the difference, the higher the difference in fuel consumption, the quicker you will recoup the difference.


Look at it this way though, the ufront capital cost is a once off, the recurrent hit's you ever week. If you can pony up a little more upfront you WILL save a few bucks each week.

If your only doing 10,000km per year, it will be three years before you break even on your upfront, but then whats resale of the diesel vs a petrol? There are lots of factors. I still stand by if you can afford it upfront, why not get better consumption figures.

[gerhard]

Agreed, economy wasn't the driver - but what I mean is, given the extra cost of diesel, is there actually *any* saving in such conditions.

Last time I looked, the price of 98RON and the price of diesel were so close as to be irrelevant to the "recoup costs" argument.

The "diesel- petrol recoup outlay" argument is a crock, anyway you look at it.

If you were after cheap motoring, you'd maybe get a base model I30 diesel - the VW wouldn't get a look in due to price.

So you bought your car because you liked the diesel way, and you liked the VW way - don't beat yourself up wondering if you made the right decision.

You did.

What's that - you didn't? - then change the car and get on with life.

When I get my GTI (next week is looking good ) I will be using schmidtloads of less fuel than I am at the moment running around in the Jack.

I love the Jack and will keep it for the High Country jaunts, where the GTI is totally incompetent

As a final matter of interest - how many people do you know who have improved their financial position dramatically by saving $10 a week on fuel?

[Preen59]

^^^ Fair comment.

I agree totally. And the thing is, if you're only saving about 10 bucks or so a week, unless you're VERY meticulous, you'll just spend that on something else..

[Paul_OH]

We've had our GT TSI for about 3 weeks now and just clicked over 1500km. I'm actually quite impressed with the economy at 8.6 l/100km with a fairly hard break-in process. Hard acceleration but not revving over 5500-6000rpm (redline at 7000 and cutout at 7500rpm). Our (my) driving has been approx 50% inner city/suburban and 50% freeway/highway so pretty much a combined average as per manufacturer standards. On the highway it's giving around 5.8 l/100km at 100km/h so very pleased and it's still very tight.
We're currently getting around 650km per tank on those figures at an average cost of $1.58 per litre.
We looked at the GT TDI but couldn't justify the cost increase as we would have needed to travel approx 27000km per year overy 5 years to recoup the difference, we currently travel approx 20K per year.

Don't get me wrong, I bet you love you car and it IS a great car, just enjoy it and don't worry about a $ here or there.

Paul

[Sharkie]

I have a few workmates with both GTI's and TDI's. Driving into the BNE CBD their fuel consumption is about the same, much to the disgust of the TDI owners......

A TDI is only really efficient at cruising speed on the highway where you're not using the turbo. The moment the turbo starts spooling up say goodbye to fuel efficiency. You get punished for having fun in any turbo car, be it petrol or diesel.