Diesel cars (toxic tax) announced

Sporky

Or you could have selected different bits of the article...

The research team said a mandatory imposition of filters on all vehicles was premature.

hywelg

The one thing is certain. The government cannot allow a drastic change of direction because of the costs involved for voters, companies buying company cars  and businesses running vans. 

They will allow local government to make a small charge for the most poluting vehicles,  will.probably increase diesel fuel cost, will change company car rules for BIK, and capital allowances for vehicle purchases. But probably by a small amount at first but signalling yearly increases in future. 

What they cannot do, (at least I'm hoping they can't) is penalise vehicles that comply with the current highest standard, because that's really unfair if alternatives do not exist. 

ICBM

hywelg said:

What they cannot do, (at least I'm hoping they can't) is penalise vehicles that comply with the current highest standard, because that's really unfair if alternatives do not exist. 

They can. But they won't, at least not unless either

a - they've just won an election with an unassailable majority and want to get it over with while there's still five years until the next one.

or

b - they can convincingly blame the need to do it on the last government of the other party.

Since both of those things are likely to be true soon, you just have to hope that they won't.

ToneControl

Axe_meister said:

ToneControl said:

Axe_meister said:

Yes force is changing (well being equalised) but force is mass x acceration. We had many a debate at uni about this. It all depends on your frame of reference. 

at Uni?
this is O level maths

Degree in Aero Engineering. Of course our equations would take into loss of mass due to fuel consumption, drag, friction on the road, side wind change in angle of attack if the gradient changes.

you have a resultant force vector
here's a reference for that: http://www.mathcentre.ac.uk/resources/uploaded/mc-web-mech1-5-2009.pdf
acceleration will be in the direction of that vector

Acceleration is the outcome of the force vectors acting on masses, you don't have more than one acceleration fighting against each other

Engineering lecturers often struggle when explaining maths and physics 

thomasross20

This diesel chat is one of the reasons I'm holding back on getting a Honda 1.6 iDTEC.
66mpg and Honda are super reliable (apparently)....!! 
Their Jazz does 53mpg (petrol!) but it's not the same... 
Damn...............

ToneControl

thomasross20 said:

This diesel chat is one of the reasons I'm holding back on getting a Honda 1.6 iDTEC.
66mpg and Honda are super reliable (apparently)....!! 
Their Jazz does 53mpg (petrol!) but it's not the same... 
Damn...............

fuel is a very low cost unless you do crazy miles per year
I bought my diesel anticipating 30k a year, but have so far not needed to

thomasross20

Actually you're right.... I'm focusing WAY too much on this mpg number....
I do ~15k a year. Petrol bill o old Focus was about £200 a month which I wanted to bring down. 37mpg on that. 
The Skoda 1.4 petrol averages 47mpg but I get 60mpg peak to work and 51mpg back (uphill). Out of a petrol!!
Shame it's boomy on the inside - hurts my ears - has to go!!

Axe_meister

ToneControl said:

Axe_meister said:

ToneControl said:

Axe_meister said:

Yes force is changing (well being equalised) but force is mass x acceration. We had many a debate at uni about this. It all depends on your frame of reference. 

at Uni?
this is O level maths

Degree in Aero Engineering. Of course our equations would take into loss of mass due to fuel consumption, drag, friction on the road, side wind change in angle of attack if the gradient changes.

you have a resultant force vector
here's a reference for that: http://www.mathcentre.ac.uk/resources/uploaded/mc-web-mech1-5-2009.pdf
acceleration will be in the direction of that vector

Acceleration is the outcome of the force vectors acting on masses, you don't have more than one acceleration fighting against each other

Engineering lecturers often struggle when explaining maths and physics 

But in finding out what that vector is you may have to use f=ma
with different values of a (in different directions)

Sporky

Axe_meister said:

But in finding out what that vector is you may have to use f=ma
with different values of a (in different directions)

That sounds a bit backwards - why work out the force from the acceleration?

In general I concur that acceleration is the outcome and is a single vector that results from the various forces acting on the mass.

ICBM

thomasross20 said:

This diesel chat is one of the reasons I'm holding back on getting a Honda 1.6 iDTEC.
66mpg and Honda are super reliable (apparently)....!! 
Their Jazz does 53mpg (petrol!) but it's not the same... 
Damn............…

thomasross20 said:

Actually you're right.... I'm focusing WAY too much on this mpg number....
I do ~15k a year. Petrol bill o old Focus was about £200 a month which I wanted to bring down. 37mpg on that. 
The Skoda 1.4 petrol averages 47mpg but I get 60mpg peak to work and 51mpg back (uphill). Out of a petrol!!
Shame it's boomy on the inside - hurts my ears - has to go!!

The first decision you need to make is to simply rule out a diesel.

If you're doing 15K a year, that's about 320 litres of petrol in the Skoda or 225 litres of diesel in the Honda, roughly - saving 95 litres at about £1.20 a litre, ie £114 a year… basically peanuts.

If you were doing huge mileages or looking for a type of car where diesel is the only (or only sensible) option, it would be different - but you're looking for a small-ish standard car, the very type where diesel has no advantages other than a tiny bit of fuel economy, and a whole lot of disadvantages - not least that if they do go wrong for something engine-related, they're almost always a lot more expensive to repair than a similar petrol - this from my garage mechanic.

There's also the strong possibility of much greater depreciation as diesel becomes unpopular - or maybe even penalised in places like Edinburgh - and it could end up costing you much more than that tiny saving in fuel cost.

Sporky

I concur with ICBM; at that mileage diesel is not the correct choice, unless you're towing or carrying a metric crapload of heavy stuff.

I think my mileage is marginal for diesel (not much more) but the sort of car I want/need isn't available in petrol unless you're willing to spend 50% more.

Snap

I'm a firm believer that obsessing about MPG is a waste of time. Most mainstream cars are very similar, in real world terms, when it comes to MPG and the savings to be had. We've just been hard sold the benefits of diesel for such a long time, we all believe it.

Axe_meister

Sporky said:

Axe_meister said:

But in finding out what that vector is you may have to use f=ma
with different values of a (in different directions)

That sounds a bit backwards - why work out the force from the acceleration?

In general I concur that acceleration is the outcome and is a single vector that results from the various forces acting on the mass.

Because g is acceleration = 9.8 m/s^2.

If this where a banked track on the side of a hill, You would have to calculate g1= gravity component of gradient and g2 gravity component of the bank angle.

The resultant acceleration will be zero when all the forces balance themselves out. Otherwise you fall off the track.

Sporky

Axe_meister said:

Sporky said:

Axe_meister said:

But in finding out what that vector is you may have to use f=ma
with different values of a (in different directions)

That sounds a bit backwards - why work out the force from the acceleration?

In general I concur that acceleration is the outcome and is a single vector that results from the various forces acting on the mass.

Because g is acceleration = 9.8 m/s^2.

Gravity is a force - 9.8N/kg.

9.8m/s^2 is the resulting acceleration (assuming no other forces).

It's much simpler to work in forces, then once you've combined all the forces you work out the resultant acceleration.

Axe_meister

Sporky said:

Axe_meister said:

Sporky said:

Axe_meister said:

But in finding out what that vector is you may have to use f=ma
with different values of a (in different directions)

That sounds a bit backwards - why work out the force from the acceleration?

In general I concur that acceleration is the outcome and is a single vector that results from the various forces acting on the mass.

Because g is acceleration = 9.8 m/s^2.

Gravity is a force - 9.8N/kg.

9.8m/s^2 is the resulting acceleration (assuming no other forces).

It's much simpler to work in forces, then once you've combined all the forces you work out the resultant acceleration.

g is referred to as the acceleration of gravity. Its value is 9.8 m/s2 at sea level

But what if m is changing and when you get into rockets g also changes with altitude.
What you may want to find out is, What is the force I need to exert in direction X/Y/Z to ensure I stay the same speed.
 

Sporky

Axe_meister said:

What you may want to find out is, What is the force I need to exert in direction X/Y/Z to ensure I stay the same speed.
 

Well, in that case you're definitely better off working in forces!

Axe_meister

But once you need to start intergrating or differenting based on speed/time you have to use the acceleration variable

thomasross20

@ICBM I agree - I'm right on the line where folk would say a diesel is worth it. I calculated I'd save more - I'll have to revisit the numbers. The ONLY diesel I'd have considered was the Civic 1.6 as it gets next to no bad reviews - the DPF is near the exhaust and has very few issues. 66mpg but then I'm getting 50+ from a 1.4 TFSI petrol so yeah... in that case, petrol wins. Totally agree about diesel depreciation, too..... and possibility of higher diesel price or road tax rise for diesel users. 
-> Just need to choose the right petrol! 

Axe_meister

I really recommend the new 2017 Civic.
The old one was good this one is bloody brilliant.

thomasross20

I LOVE the look of the 2017 Civic.... unfortunately I'd have to pay new prices which I'd never do and couldn't afford anyway!
The old model..... not keen on the rear bar... and the seat is too high... I keep bumping my knees off the steering wheel. 
Plus, their headrests tilt forward too much. 
But the 2017 looks good.

What about Mazda 3/6? The only thing I've read is they can be noisy. I might have to bite the bullet am get an A3 with this same amazing TFSI engine.