Do you drive significant distances and time in town traffic (10-40km/h) and still get the 20km/l (5l/100km) figures you published? I doubt that. As I said, as soon as you are out of town, I have no problem with VAG numbers.

Many people think they drive mixed use when they drive dual carriageways across town. E.g. here in the UK Milton Keynes is a town, but you can drive motorway speeds all across it, you only stop at (numerous) roundabouts.

Anyway, the whole fuel consumption thing is still a moot point as whatever you use, the new Octy fuel tank is only 50l, 5l smaller than the old one, one way or another the range has been crippled. If I wanted to save fuel by reducing weight, I would much rather fill up a70l tank to half-full, rather than have VW beancounter cripple the car's range.

Believe or not, I seriously considered buying a V6 petrol Superb a year ago as I can afford the fuel cost, but one of the main things that stopped me was 60l fuel tank (the other was the durability of DSG). I frequently travel abroad, at night autobahn speeds 60l translates to fuel stop every 1.5h (assuming 8l reserve, 52l/(15l/100km)/230km/h), ridiculous when I can drive my current Superb 2.5TDI V6 comfortably for 2h15min at the same speeds, and there are cars that will let you go for 3h, or across most/entire Germany at that speed before refuelling.

You should seriously think about getting a Helicopter !!

:think: :think: :think:

Helicopters are expensive to run

Especially at idle!

:D:D

Tapatalk'd from my HTC SXE Beats

DieselV6, fuel economy numbers aren't fiction and aren't produced by the manufacturers.

The fuel economy tests are specific and very tightly controlled. They are also directly comparable right across models and brands.

Differences between any particular drivers fuel economy and published figures is explained by two things.

Firstly individual differences in the vehicle (oils, tyres, tyre pressure, weight of junk carried, adapted tune etc).

Secondly behaviour of the driver. Where and how the vehicle is driven.

The particular problem we are seeing now, is the cars are being tweaked to give awesome results on the standard EC tests. Tweaks which give gains on the tests may not make any difference with the way you use your car.

For exmaple. The 7 speed dry DSG box gets a better result on the tests (marginally) than the manual versions. Despite the DSG being a fundamentally less efficient box than a manual.

This difference can be explained by the DSG ratios and shift points being very well suited to getting excellent results in the test. Where a manual gearbox has it's operation more heavily prescribed in the same test.

As long as you understand the differences, particularly between the tests and your own use, there is no problem.

If car A gives a 20% better test result than car B, then regardless of absolute numbers, when driven the same way you would expect car A to use less fuel.

As I stated before, I would be happy enough with fuel economy being even ~40% overstated, as long as the fuel tank was large enough.

Even my Roomster's 1.6CR DPF heavy drinker uses less fuel than petrol engines in the range in absolute terms, and anytime it goes abroad in Europe, fuel gets 30% less expensive. However, Octavia 3 has 50l fuel tank which is less than 55l previously used and is a joke given that previous engine that I used on that platform was a 1.9 and used 10% less fuel than current DPF offerings (again, that last remark is from my own experience, using the cars I bought so far). Basically, between 2002 and now the range of the car got reduced by 20%+ and it is now at a point where it is no longer convenient.

It is really the fuel tank size that is the issue. And there still remains doubt on whether full size spare is planned for the car (as opposed to space saver). The rear suspension will likely be better for the vRS diesel versions and of course 4x4.

Edited 14 January, 201313 yr by dieselV6

Do you drive significant distances and time in town traffic (10-40km/h) and still get the 20km/l (5l/100km) figures you published? I doubt that. As I said, as soon as you are out of town, I have no problem with VAG numbers.

Many people think they drive mixed use when they drive dual carriageways across town. E.g. here in the UK Milton Keynes is a town, but you can drive motorway speeds all across it, you only stop at (numerous) roundabouts.

Anyway, the whole fuel consumption thing is still a moot point as whatever you use, the new Octy fuel tank is only 50l, 5l smaller than the old one, one way or another the range has been crippled. If I wanted to save fuel by reducing weight, I would much rather fill up a70l tank to half-full, rather than have VW beancounter cripple the car's range.

Believe or not, I seriously considered buying a V6 petrol Superb a year ago as I can afford the fuel cost, but one of the main things that stopped me was 60l fuel tank (the other was the durability of DSG). I frequently travel abroad, at night autobahn speeds 60l translates to fuel stop every 1.5h (assuming 8l reserve, 52l/(15l/100km)/230km/h), ridiculous when I can drive my current Superb 2.5TDI V6 comfortably for 2h15min at the same speeds, and there are cars that will let you go for 3h, or across most/entire Germany at that speed before refuelling.

Yes, that is the figures for mixed driving (motorway/city/countryroads). For a 1.6 TDI. With DPF. In the winter. With wintertyres. With no special "eco friendly" precautions. Without using start/stop. So, my car must be broken? :-)

Well, I guess mine must be broken then, in that very special way that produces no fault codes whatsoever and makes fuel consumption 40% worse than brochure numbers.

It also frequently does quiet DPF regen (no check light), and only does full regen every 500-600 miles.Or perhaps I should wait another 6k miles for the "engine to learn my driving habits"?

The Roomster has maxidot gear shift change indicator, so it is driven as manufacturer suggests. Plus I was happy with VW engines fuel economy numbers for the previous 240k miles total on Mk1 Octy. The 40% difference to test numbers is disgraceful.

One final question, does your DPF regen every 120 miles or so (light on the dashboard)? If yes, then the engine software is the difference, as mine is just squirting fuel at return stroke into DPF to keep it at correct temperature. PDs did regen every 120 miles and while they did have clogged DPF problems, fuel economy was not a big issue.

Operator error.

Yes, especially the 500 mile regen as opposed to 120 miles widely reported for earlier engines. I block regens with my mind

Looks like you are running out of facts, mate. http://www.briskoda.net/forums/topic/261482-technical-guides-diesel-petrol/#entry3096949

Edited 18 January, 201313 yr by dieselV6

Out of facts? Nope, just a bit pointless when they keep getting ignored in favour of really bizarre 1.9 vs 2.5 accounts.

Well, I guess mine must be broken then, in that very special way that produces no fault codes whatsoever and makes fuel consumption 40% worse than brochure numbers.

It also frequently does quiet DPF regen (no check light), and only does full regen every 500-600 miles.Or perhaps I should wait another 6k miles for the "engine to learn my driving habits"?

The Roomster has maxidot gear shift change indicator, so it is driven as manufacturer suggests. Plus I was happy with VW engines fuel economy numbers for the previous 240k miles total on Mk1 Octy. The 40% difference to test numbers is disgraceful.

One final question, does your DPF regen every 120 miles or so (light on the dashboard)? If yes, then the engine software is the difference, as mine is just squirting fuel at return stroke into DPF to keep it at correct temperature. PDs did regen every 120 miles and while they did have clogged DPF problems, fuel economy was not a big issue.

Get a mk2 2.0 tdi pd scout these are obviously the best Octy available, mine has averaged 53mpg over the last 2500 miles and has only put the DPF regen light on 4 times in the last 50k miles. ;-) can't be far off some of the green lines.

I already envied you after reading mk2 2.0tdi pd scout, no need to boast any further

Yes, I plan to get Octy 3 from Ireland with a similar spec, probably 2-4 years down the line when pricing comes back to earth and my Mk1 Superb is old enough/dies.

Likely either vRS or 4x4, depends if they put 2.0CR 184bhp engine in the 4x4, with underbody protection as on the Scout, full size spare same as other wheels on the car, and will look into convincing insurance company that installing aux fuel tank does not mean I have a death wish

Well, I guess mine must be broken then, in that very special way that produces no fault codes whatsoever and makes fuel consumption 40% worse than brochure numbers.

It also frequently does quiet DPF regen (no check light), and only does full regen every 500-600 miles.Or perhaps I should wait another 6k miles for the "engine to learn my driving habits"?

The Roomster has maxidot gear shift change indicator, so it is driven as manufacturer suggests. Plus I was happy with VW engines fuel economy numbers for the previous 240k miles total on Mk1 Octy. The 40% difference to test numbers is disgraceful.

One final question, does your DPF regen every 120 miles or so (light on the dashboard)? If yes, then the engine software is the difference, as mine is just squirting fuel at return stroke into DPF to keep it at correct temperature. PDs did regen every 120 miles and while they did have clogged DPF problems, fuel economy was not a big issue.

The car has now done 39000 km and the DPF light has never been on. It will only light up if you are driving to many short trips, so the car is unable to regenerate the DPF "silently". So, I´m only seeing it when I put the ignition on

I was speaking to a development engineer from a car company last week. We chatted about this very topic. He pointed out that these are lab tests which are only meant to demonstrate comparative results between different cars in the conditions tested. But manufacturers all manipulate the results to their benefit by various means. Individual cars vary slightly, so they test many before selecting the one(s) that perform best. Nitrogen filled tyres help. Everything is double checked for maximum efficiency such as bearing tension etc. Just 0.1 l/100kms better is worth chasing particularly if it drops you from say 9.0 to 8.9..

But the main differences between claimed figures and real world results occur with driver behaviour and road conditions such as traffic, road type and so on. In my Superb Combi V6, I get 14.4l/100km commuting in inner suburban Sydney - or around 9.5l/100km commuting in suburban Canberra, because the road and traffic conditions are dramatically different. I can even average 7l/100km if I am willing to drive at 80km/h on a flat, open country road - as I had to recently because of some damage. Necessary, but painful. That is huge variation.

Frankly, I really only care about fuel consumption as a topic of interest, whether I can afford to run the car and whether the cost benefit works for me. I could have bought a 2.0TDI Superb and reduced my fuel cost noticeably (I do 25-30,000kms annually) but the diesel is (comparatively) sluggish, noisy and boring to drive. Each to their own.