Things you always wanted to know the answer to [Vol. 3]

[P-Jay]

rohrl said:

GokTweed said:

Why are car companies still building cars with steel when aluminium is easier to work with nowadays and readily available, not to mention the strength and weight benefits etc?

I get why they wouldn't on a cheap model because it's a more expensive technology, but for their big family barges etc. to help reduce weight and economy? Shirley it's an easy fix to get the mpg's up by making the car lighter?

The bodywork isn't as big as a percentage of the car's weight as you'd think (you still have the same glass, interior, suspension, wheels, engine, transmission, electrics etc.) and thus the weight saving from building in aluminium isn't that great.

Makes sense, Range Rover quoted some obscenely low weight for the chassis of their latest RR didn't they? The final car still weighs two and a bit tonnes.

[GokTweed]

P-Jay said:

rohrl said:

GokTweed said:

Why are car companies still building cars with steel when aluminium is easier to work with nowadays and readily available, not to mention the strength and weight benefits etc?

I get why they wouldn't on a cheap model because it's a more expensive technology, but for their big family barges etc. to help reduce weight and economy? Shirley it's an easy fix to get the mpg's up by making the car lighter?

The bodywork isn't as big as a percentage of the car's weight as you'd think (you still have the same glass, interior, suspension, wheels, engine, transmission, electrics etc.) and thus the weight saving from building in aluminium isn't that great.

Makes sense, Range Rover quoted some obscenely low weight for the chassis of their latest RR didn't they? The final car still weighs two and a bit tonnes.

They shaved off something like 700kg from the car though by using aluminium. surely even 100kg off a family car would be worth it in the long run?

[SpeckledJim]

GokTweed said:

P-Jay said:

rohrl said:

GokTweed said:

Why are car companies still building cars with steel when aluminium is easier to work with nowadays and readily available, not to mention the strength and weight benefits etc?

I get why they wouldn't on a cheap model because it's a more expensive technology, but for their big family barges etc. to help reduce weight and economy? Shirley it's an easy fix to get the mpg's up by making the car lighter?

The bodywork isn't as big as a percentage of the car's weight as you'd think (you still have the same glass, interior, suspension, wheels, engine, transmission, electrics etc.) and thus the weight saving from building in aluminium isn't that great.

Makes sense, Range Rover quoted some obscenely low weight for the chassis of their latest RR didn't they? The final car still weighs two and a bit tonnes.

They shaved off something like 700kg from the car though by using aluminium. surely even 100kg off a family car would be worth it in the long run?

I thought it had been established that they were comparing the very heaviest version of the old RR with the very lightest version of the new RR, and thus the stated 700kg saved was nonsense of the first order?

[Dodsy]

I think Aluminium makes a significant difference although not the 700kg claimed for the RR. Take the example of the Jag S type vs the XJ. Same engine, drivetrain, suspension, brakes etc but the bigger XJ is made from aluminium. Its 40kg lighter and manages to get to 60 0.3 secs quicker with the same engine and gearbox.

Weight
S Type 1830Kg
XJ 1790Kg

Length

S Type 4.91m
XJ 5.09m

Width
S Type 2.06m
XJ 2.11m

[Tango13]

A general rule of thumb is that aluminium is 1/3 the weight of steel but has 1/3 the strength so you need 3x as much aluminium for the same strength thus wiping out any weight savings.

One benefit of aluminium is it's easier to build a monocoque with it, you simply glue it together instead of expensive spot or seam welding.

[Negative Creep]

A letter arrived today with these attached, so I assume they're still legal to use. Any idea how old they are?

[TheEnd]

They seem to be from about 1980.

[GokTweed]

Tango13 said:

A general rule of thumb is that aluminium is 1/3 the weight of steel but has 1/3 the strength so you need 3x as much aluminium for the same strength thus wiping out any weight savings.

One benefit of aluminium is it's easier to build a monocoque with it, you simply glue it together instead of expensive spot or seam welding.

Don't you mean stiffness rather than strength? I'm not an engineer but I thought strength isn't an issue when building cars with aluminium, it's the deformation that it can undergo because the material is less dense? unless you meant fatigue strength?

[Dr Jekyll]

Why do some people read magazines from the back? My theory is it's to indicate that they are just flicking through and that they are far too busy to read the articles properly.

[scarble]

GokTweed said:

Don't you mean stiffness rather than strength? I'm not an engineer but I thought strength isn't an issue when building cars with aluminium, it's the deformation that it can undergo because the material is less dense? unless you meant fatigue strength?

If strength isn't a measure of propensity to deformation, what is it?
Nothing to do with the density though as strength, stiffness and density are not inextricably linked.
The specific strength or specific modulous depends on the alloy, some steels are weaker than some aluminium alloys and some are much stronger.
However using a part that is 3 times bigger than the steel equivalent gives bending strength benefits, hence why box sections and tubes and stuff are used for things.
Imagine if your steel tube for your roll cage or climbing frame or whatever was instead just a solid piece of steel, with the same amount of material, but overall much smaller. It'd bend pretty easy right?

[Issi]

Have the UK got the monopoly on regional accents?

Is a Frankfurt accent noticeably different than a Dusseldorf accent?

Are there the equivalent of Brummies or Scousers in Spain?

Do people from Poitiers make fun at those from Caen, because they speak funny?

[walm]

Issi said:

Are there the equivalent of Brummies or Scousers in Spain?

Catalonians speak an entirely different language. So yes.

[Dr Jekyll]

Regional accents in the US are pretty obvious. People I know who speak French reckon Provence sounds different from the rest of France.

[steveo3002]

in ww2 , say you were a non forces civilain in the uk so a farmer or whatever , and that the germans had invaded the uk , could you have killed the germans legaly or would it have been murder

[Issi]

Dr Jekyll said:

Regional accents in the US are pretty obvious. People I know who speak French reckon Provence sounds different from the rest of France.

I'm aware that there is a marked difference between let's say Texas and Boston, but would a New Yorker immediately be able to know that another person was from Pittsburgh just after chatting for a couple of minutes?

Thinking about it, in the cellar bar scene in Inglorious Basterds, the SS chap picks up on the good guys accents, and even mentions that he couldn't place Michael Fassbenders accent.

I think I've just answered my own query!

[Rickyy]

Do birds like to st on shiny things? Seagulls in particular.

Every time I leave my MX5 out of the garage, it gets covered in bird st. I park amongst 10 other cars and only mine and my neighbours silver Focus ever seem to get st on.

[Shaolin]

Rickyy said:

Do birds like to st on shiny things?

Yes. There's an overhead cable that goes across my front garden, it must be about 40 feet long. Sometimes I park the car under it, this is when the local pigeons decide to sit on the bit immediately above my car (width-wise) and relieve themselves. There is hardly ever any bird st along the line of the cable anywhere else of it's span.

[P-Jay]

Dr Jekyll said:

Why do some people read magazines from the back? My theory is it's to indicate that they are just flicking through and that they are far too busy to read the articles properly.

I have two crackpot theories

Firstly it comes from Childhood - most of us have had an Argos catalogue in the house at some time during our childhood - I'd always dive straight to the back, that's where the toys were!

Or... 90% or more of people are right-handed, books / magazines and whatnot are left-handed really, to read them correctly you need hold with your right hand, but manipulate it with your left hand

[marshalla]

Dr Jekyll said:

Why do some people read magazines from the back? My theory is it's to indicate that they are just flicking through and that they are far too busy to read the articles properly.

A lot of magazines have the regular articles towards the back (e.g. in most classic car mags. the "our cars" stories are the last thing before the adverts and there's usually an interesting nostalgia piece or guest writer on the very last page. Some people are more interested in these regular pieces than the "main" articles.

[P-Jay]

steveo3002 said:

in ww2 , say you were a non forces civilain in the uk so a farmer or whatever , and that the germans had invaded the uk , could you have killed the germans legaly or would it have been murder

I'm not sure how the law sits - but in reality I'd bet money it would come down to who won the war - if we won (assuming that of course your hypothetical invasion of mainland Britain is part of a hypothetical version of WWII) then you would have been a 'Brave Resistance Fighter' or simply a unenlisted member of the home guard, however if we lost then you'd be a dangerous terrorist (or whatever they called them back then) and shot.

Resistance/Freedom/Guerrilla Fighter or Terrorist - as ever it really depends on which side you're on.