OT: Dieselgate

[newshound]

An excellent critique of EPCs here (and some other good stuff)

[Tim+]

I?ve never felt that in the UK (and Europe) we?ve had much of a case for claiming against VAG. In America, the VWs were very heavily promoted as being ?clean? and not polluting. This was never really a selling point in the UK. They gave us smooth, economical diesels with nice driving characteristics. I liked them.

They arguably went a bit OTT getting around the regulations but that?s what all manufacturers do.

Tim

[Fredxx]

<Sigh> This thread is about diesels and Dieselgate.

Even with petrol cars using stoichiometric mixtures makes engines run beautifully. Rich mixtures foul up plugs for one.

[Tim+]

Indeed. My wife?s Golf was built in the middle of the period of affected vehicles but was never recalled. Like yours, pre-ad-blu. Possibly because it wasn?t the highest power version of the 2L diesel that was available at the time.

Tim

[Tim Lamb]

Ah!

I just happen to have a recently acquired 9 year old Passat. As you say the comfort/construction/performance is excellent. However, as an elderly technology averse user, I find the amount of totally unnecessary (and not totally reliable) electronic gizmos a pain.

If delivery has escaped the floods in Germany, you could assist in fitting a rear wheel ABS sensor this weekend!

I worry that the next generation of road vehicles will only be capable of being driven by young people distracted from their mother's breast by the screen on a mobile phone:-(

I suppose an investment in road recovery specialists or main agent garages might be rewarding.

[Theo]

I do, I pay close attention to them in fact. Not so much for the band letter or the cost numbers, which are baked in at the time the EPC was produced (plenty of wind turbines and >10K solar panel systems on 10yo EPCs) and never updated afterwards. But for the statements of fact, like does it have cavity or solid walls, what kind of heating does it have, etc. For example if it says a place has storage heaters only I'd be subtracting 10K from the price in my head.

I recently had one done. £55 for about 30 minutes, I got what I paid for, which is not very much.

What's frustrating is that I actually wanted a full house heat loss calculation, but that's not part of the EPC and the assessors won't do it. The RdSAP in the EPC has a collection of guesstimates and a very simplified methodology. A full SAP is primarily for new buildings and is done off the plans.

So I did my own full SAP, which came out roughly what I expected. But what's annoying is that every heating engineer I ask for a quote has to do their own heat loss - it would be much better if that was part of the EPC and they could then quote based on that information.

I can understand doing a full SAP might be tricky for many properties due to lack of access, and so full of so many assumptions as to be useless. I did see an interesting project where they measure energy consumption via smart meters and temperature and use that to determine heat losses. That sounds a bit difficult if you have an EV (since you're expending energy outside the house) but otherwise would seem to make sense.

I'd guess the problem is that anything that's mandatory needs a methodology that works for all the corner cases, and that's where the difficulties lie.

Theo

[Dave Plowman (News]

It's going to make a difference as ULEZ get introduced. Vehicles which pass the Euro standard get free access. Those that don't have to pay. And there are countless relatively recent deisels that passed the test in the lab, but fiddled, and don't in actual use.

[Dave Plowman (News]

Bollocks. You get a considerable increase in power by going richer than stoich. Cars without a cat. develop maximum power at something like

12.5:1. And at cruise, you can get better MPG by running lean.

[Tim Lamb]

In message [e-mail]>, "Dave Plowman (News)" [e-mail]> writes

Hence my recent elevation to a diesel Passat! The previous owner has gone electric.

Reading the handbook leads to an impression that the engine management system is constantly varying the fuel injection. Constant speed, level highway and the dash display indicates 200mpg!

[Fredxx]

Given your previous lack of understanding of power and torque, I can see why you might think an engine run on a rich mixture making black smoke would run 'beautifully'. Some of us with real world experience know that misfire from fouled plugs is a reality, and fuel wash will lead to excessive bore wear is also real issue.

[The Natural Philosopher]

Of course it is. diesel power is entirely a matter of how much fuel is injected.

I noticed that the MPG on my diesel is utterly contingent on how many times I have to use the brakes. getting it up to speed again takes at least the same amount of fuel as pootling along at a constant speed for ten miles does.

[Tim Lamb]

Indeed. I was aiming for whether an emissions test at constant speed on a rolling road would ever produce a realistic measure of *on the road* pollutants.

[Dave Plowman (News]

Carry on making yourself look a bigger fool. You could even do some research before posting crap.

[Nick Cat]

Unfortunately the info in these oversimplified surveys is not factual. Finding out whether an 1800s house has cavity or solid walls is not as simple as many believe it is, ie you can't tell by looking at the brickwork pattern because faking patterns was widespread normal practice. Also it's not as simple as cavity or no cavity, there are also plenty of bridged cavity and narrow cavity walls. And a simplified survey really has no clue about any of this. And of course there are other construction factors that make major differences to real world fuel consumption, such as level of underfloor ventilation and floor construction details determining heat loss there. Then there are crittall windows, which are a thermal abomination, whether the cavity is open top & bottom or not etc etc.