Questions that need to be answered

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Mr. Dazzle
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Re: Questions that need to be answered

Post by Mr. Dazzle »

I'd guess its cause engines were typically done in cubic inches / freedom units. Cubic centimeters feels like less of a surrender to the commie metric system, despite it being both A) metric, and B)the same size as a millilitre.
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Re: Questions that need to be answered

Post by Count Steer »

Mr. Dazzle wrote: Fri Feb 07, 2025 8:11 am I'd guess its cause engines were typically done in cubic inches / freedom units. Cubic centimeters feels like less of a surrender to the commie metric system, despite it being both A) metric, and B)the same size as a millilitre.
Some of our Mint Imperial units still work bestest though. eg mph and psi. Them forrin equivalents, inc the Merkins with their squitty little 'gallons', are rubbish.

Edit: bhp is :thumbup: too.
The plural of 'anecdote' is not 'data'.
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Re: Questions that need to be answered

Post by Pirahna »

Saga Lout wrote: Fri Feb 07, 2025 4:55 am Why do we use cc and litre for engine sizes? We should be consistent and use millilitres and litres.

(Or centilitres, :D)
Perhaps a change to cups or tablespoons?
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Re: Questions that need to be answered

Post by Mr. Dazzle »

Count Steer wrote: Fri Feb 07, 2025 8:44 am
Mr. Dazzle wrote: Fri Feb 07, 2025 8:11 am I'd guess its cause engines were typically done in cubic inches / freedom units. Cubic centimeters feels like less of a surrender to the commie metric system, despite it being both A) metric, and B)the same size as a millilitre.
Some of our Mint Imperial units still work bestest though. eg mph and psi. Them forrin equivalents, inc the Merkins with their squitty little 'gallons', are rubbish.

Edit: bhp is :thumbup: too.
My current car does tyre pressures in kPa on it's dashboard systems, the last one did too (funny that, what with it being basically the same model :D). I could no doubt go into the settings and change it, but honestly I CBA and I've just recalibrated my thinking :lol: Correct pressure is 280kPa.

2.8bar if you prefer, which is what lots of pumps read in.
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Re: Questions that need to be answered

Post by Horse »

Count Steer wrote: Fri Feb 07, 2025 8:44 am
Mr. Dazzle wrote: Fri Feb 07, 2025 8:11 am I'd guess its cause engines were typically done in cubic inches / freedom units. Cubic centimeters feels like less of a surrender to the commie metric system, despite it being both A) metric, and B)the same size as a millilitre.
Some of our Mint Imperial units still work bestest though. eg mph and psi. Them forrin equivalents, inc the Merkins with their squitty little 'gallons', are rubbish.

Edit: bhp is :thumbup: too.
NY previous previous proper job (before a sideways shift, then redundancy) involved working in both imperial and metric.

Conversions never caused problems, oh no, never :roll:

We were designing printed circuit boards, where a track width of a single digit (e.g. "8 thou") is much easier to determine (by the electronics engineer) and describe than its metric equivalent.
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Re: Questions that need to be answered

Post by Rockburner »

Mr. Dazzle wrote: Fri Feb 07, 2025 9:15 am
Count Steer wrote: Fri Feb 07, 2025 8:44 am
Mr. Dazzle wrote: Fri Feb 07, 2025 8:11 am I'd guess its cause engines were typically done in cubic inches / freedom units. Cubic centimeters feels like less of a surrender to the commie metric system, despite it being both A) metric, and B)the same size as a millilitre.
Some of our Mint Imperial units still work bestest though. eg mph and psi. Them forrin equivalents, inc the Merkins with their squitty little 'gallons', are rubbish.

Edit: bhp is :thumbup: too.
My current car does tyre pressures in kPa on it's dashboard systems, the last one did too (funny that, what with it being basically the same model :D). I could no doubt go into the settings and change it, but honestly I CBA and I've just recalibrated my thinking :lol: Correct pressure is 280kPa.

2.8bar if you prefer, which is what lots of pumps read in.
40psi??

fecking hell, what are you driving, a Routemaster???
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Re: Questions that need to be answered

Post by Count Steer »

I was one of those 'lucky' ones that had to learn the traditional UK system and CGS and MKS. :(

At Uni we had an old, quite eccentric, physics lecturer who said 'Units? Bah. Nothing to be afraid of. Now, calculate the emf - in V/m and gauss - developed by a metal ship's mast. The mast is x cubits long, the ship is travelling through the earth's field on an ESE bearing at y leagues per fortnight. Crack on'. :lol:
The plural of 'anecdote' is not 'data'.
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Re: Questions that need to be answered

Post by Mr. Dazzle »

Rockburner wrote: Fri Feb 07, 2025 9:24 am
40psi??

fecking hell, what are you driving, a Routemaster???
Yeah I was a bit surprised too, but that's the number. It's a fairly typical big German saloon.

The old one, which was nearly the same car (even the same wheel design) was 270kPa. For some reason petrol engines add those last 10kPa.
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Re: Questions that need to be answered

Post by Saga Lout »

My point was why do we use a solid (or volume) measure, i.e. cubic centimetres, for small engines but use a liquid measure, i.e. litres, for larger engines? My guess is: because we do, that's why. :)
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Re: Questions that need to be answered

Post by MrLongbeard »

A cold beer's got twelve ounces, A good truck's got maybe three hundred thousand.
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Re: Questions that need to be answered

Post by Timmy »

Rockburner wrote: Fri Feb 07, 2025 9:24 am
Mr. Dazzle wrote: Fri Feb 07, 2025 9:15 am
Count Steer wrote: Fri Feb 07, 2025 8:44 am

Some of our Mint Imperial units still work bestest though. eg mph and psi. Them forrin equivalents, inc the Merkins with their squitty little 'gallons', are rubbish.

Edit: bhp is :thumbup: too.
My current car does tyre pressures in kPa on it's dashboard systems, the last one did too (funny that, what with it being basically the same model :D). I could no doubt go into the settings and change it, but honestly I CBA and I've just recalibrated my thinking :lol: Correct pressure is 280kPa.

2.8bar if you prefer, which is what lots of pumps read in.
40psi??

fecking hell, what are you driving, a Routemaster???
My car is the first car I've ever had where the front and back tyres are different pressures, 43 psi front, 33 psi rear. Bloody Germans
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Re: Questions that need to be answered

Post by Mr. Dazzle »

Saga Lout wrote: Fri Feb 07, 2025 9:53 am My point was why do we use a solid (or volume) measure, i.e. cubic centimetres, for small engines but use a liquid measure, i.e. litres, for larger engines? My guess is: because we do, that's why. :)
Litres aren't a liquid measure, they're also a measure of volume. Hence why you have balloons measured in litres for example.
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Re: Questions that need to be answered

Post by Pirahna »

My T6 Kombi runs 58psi in the front and somewhere between 50 and 58psi in the back.
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Re: Questions that need to be answered

Post by Rockburner »

Pirahna wrote: Fri Feb 07, 2025 10:32 am My T6 Kombi runs 58psi in the front and somewhere between 50 and 58psi in the back.
High or low profile tyres?

I "believe" (but not sure) that lower profile tyres would need a higher pressure to ensure that any bigger bumps don't incur tyre-carcass > wheel rim interfaces.
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Re: Questions that need to be answered

Post by Mr. Dazzle »

I was gonna say mine aren't low profile, but that's not true, they probably are - it's just that our mental calibration of what 'low profile' means has shifted. They're 255/35.

They're also lined with noise abating foam :thumbup:

All of which makes them nearly £300 to replace when you get a puncture :lol:
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Re: Questions that need to be answered

Post by Pirahna »

Rockburner wrote: Fri Feb 07, 2025 12:00 pm
Pirahna wrote: Fri Feb 07, 2025 10:32 am My T6 Kombi runs 58psi in the front and somewhere between 50 and 58psi in the back.
High or low profile tyres?

I "believe" (but not sure) that lower profile tyres would need a higher pressure to ensure that any bigger bumps don't incur tyre-carcass > wheel rim interfaces.
215/60/17 standard VW fitment. I had some 70 profile tyres on the Crafter which were at 70psi.
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Re: Questions that need to be answered

Post by Cousin Jack »

Mr. Dazzle wrote: Fri Feb 07, 2025 12:42 pm I was gonna say mine aren't low profile, but that's not true, they probably are - it's just that our mental calibration of what 'low profile' means has shifted. They're 255/35.

They're also lined with noise abating foam :thumbup:

All of which makes them nearly £300 to replace when you get a puncture :lol:
And they will need replacing. Same size as mine, and they last about 10k miles. :cry:
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Re: Questions that need to be answered

Post by Mr. Dazzle »

Cousin Jack wrote: Fri Feb 07, 2025 1:27 pm
Mr. Dazzle wrote: Fri Feb 07, 2025 12:42 pm I was gonna say mine aren't low profile, but that's not true, they probably are - it's just that our mental calibration of what 'low profile' means has shifted. They're 255/35.

They're also lined with noise abating foam :thumbup:

All of which makes them nearly £300 to replace when you get a puncture :lol:
And they will need replacing. Same size as mine, and they last about 10k miles. :cry:
Did 18k on the last set before giving the car back, they still had 3.1mm left. Fleet services have got a nifty little doodad in the floor, you drive over it as you go into the returns bay and it measures all four tyres.

I was worried for a moment, 'cause you have to give the cars back with >3mm of tread, but I wasn't aware the 18 month leases had a bigger tread wear allowance and I could have gone down to 2mm. Shoulda done some doughnuts in the carpark.

This was on a 250bhp rear wheel drive car too and I wouldn't say I drive like a granny.
Last edited by Mr. Dazzle on Fri Feb 07, 2025 1:34 pm, edited 1 time in total.
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Re: Questions that need to be answered

Post by Saga Lout »

Pirahna wrote: Fri Feb 07, 2025 1:19 pm
Rockburner wrote: Fri Feb 07, 2025 12:00 pm
Pirahna wrote: Fri Feb 07, 2025 10:32 am My T6 Kombi runs 58psi in the front and somewhere between 50 and 58psi in the back.
High or low profile tyres?

I "believe" (but not sure) that lower profile tyres would need a higher pressure to ensure that any bigger bumps don't incur tyre-carcass > wheel rim interfaces.
215/60/17 standard VW fitment. I had some 70 profile tyres on the Crafter which were at 70psi.
My Mazda has 225/45R19, the slightly lower spec model has 225/55R17, the manual says they both need 33psi.
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Re: Questions that need to be answered

Post by Pirahna »

Saga Lout wrote: Fri Feb 07, 2025 1:34 pm
Pirahna wrote: Fri Feb 07, 2025 1:19 pm
Rockburner wrote: Fri Feb 07, 2025 12:00 pm

High or low profile tyres?

I "believe" (but not sure) that lower profile tyres would need a higher pressure to ensure that any bigger bumps don't incur tyre-carcass > wheel rim interfaces.
215/60/17 standard VW fitment. I had some 70 profile tyres on the Crafter which were at 70psi.
My Mazda has 225/45R19, the slightly lower spec model has 225/55R17, the manual says they both need 33psi.
Your car isn't a van. I only made the original comment on reply to someone who was surprised at higher tye pressures. From memory I think my Caddy ran the fronts at 40psi. My Duster has the same size tyres as the T6 and runs 33psi.
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