|
700/900 Series General Forum for the Volvo 740, 760, 780, 940, 960 & S/V90 cars |
Information |
|
Wheel fitment 940.Views : 8504 Replies : 67Users Viewing This Thread : |
|
Thread Tools | Display Modes |
Oct 12th, 2018, 22:52 | #41 | |
Premier Member
Last Online: Yesterday 23:53
Join Date: May 2012
Location: Lakenheath
|
Quote:
Go back 30+ years and i had a 144 DL auto running the original fit 165/15 tyres - standard profile which i believe is 78. About 10mm smaller in diameter than your 195/65s (which will almost certainly help your speedo accuracy) and that winter was quite harsh with snow everywhere. I picked a colleague up on my way to work each day, she lived on an estate down in a dip with only two roads out, both steep hills. One morning after witnessing a Land-Rover spinning all 4 wheels and slithering backwards into the kerb, i had a go and just drove straight up - a little sideways action halfway up where the Landy had warmed the snow and turned it to ice but other than that, as if the weather wasn't bad. His tyres were much wider so had simply crushed the snow and flattened it. Use some butter to see the different effect. Use the blade of a knife as if cutting it to represent the skinny tyre, turn it 90 degrees to represent the wide, low profile tyre and push each different way into the butter with the knife. Which gets to the butter dish easier? Get the tyres to the butter dish/road easier with whatever width tyres and you get more grip - simples. Squash the butter/snow with extra wide tyres and you don't get to the butter dish/road.
__________________
Cheers Dave Next Door to Top-Gun with a Honda CR-V & S Type Jag Volvo gone but not forgotten........ |
|
Oct 12th, 2018, 22:59 | #42 | |
Premier Member
Last Online: Yesterday 23:53
Join Date: May 2012
Location: Lakenheath
|
Quote:
To get the speedo more or less accurate (+/- 1mph of the indicated speed) i would need to fit 205/70/15 tyres. Like i said, Volvo speedos are notoriously over-optimistic. Your "fractional error" is the error based on the assumption your speedo is accurate to start with. Factor in a speedo that reads a good 10% over in the first place and it will be a lot more! The app is free, try it and you'll be surprised! Even on 205/55/16 which are about 2mm bigger diameter than 195/65/15 if memory serves (without checking - might be 2mm under) you'll almost certainly find about a 6% over-read on the speedo now.
__________________
Cheers Dave Next Door to Top-Gun with a Honda CR-V & S Type Jag Volvo gone but not forgotten........ |
|
Oct 12th, 2018, 23:05 | #43 |
Premier Member
Last Online: Oct 26th, 2023 20:42
Join Date: Jun 2010
Location: Thurrock
|
Well. I wonder about regional variations. Interesting.
30+ years. About 1990? There was some brief heavy snow about then. On the Thursday I walked some miles home. On the Friday I was one of few who got to work, walking some miles. On Saturday because I had snow chains I was driving happily about almost deserted roads. Very handy because my aged parents needed a vist and shopping. Otherwise goodness know, Dad would probably have gone shopping, fallen over, EEK. My second hand experience of tall skinny tyres is a chap who in the really serious snows of the 1960s made excellent progress with his sit up and beg Ford Pop. I would guess his experience and yours were with "ordinary" tyres? Modern winter tyre reviews show seriously impressive results for modern winter tyres including in snow. And they don't mention tall and skinny. So far as I know, countries that require M&S tyres in winter don't make exceptions for tall and skinny tyres. I don't know. |
Oct 12th, 2018, 23:11 | #44 |
Master Member
Last Online: Yesterday 23:35
Join Date: Dec 2011
Location: Surrey
|
I've never had a speedo read 10% over in any car I've owned David. And there have been more than a few !
This speedo (when it behaves itself) is almost bang on.... I dunno where you're getting these figures. I'm beginning to form the impression that they're not from an entirely scientific source....see my previous post.... |
Oct 12th, 2018, 23:14 | #45 |
Master Member
Last Online: Yesterday 23:35
Join Date: Dec 2011
Location: Surrey
|
Tall and skinny you say ? Time to get the motorbike out as its so useful in the snow....like a knife through butter !
Speaking of butter, in order to replicate your butter test, do I use salted or unsalted ? Last edited by XCR; Oct 12th, 2018 at 23:17. |
The Following User Says Thank You to XCR For This Useful Post: |
Oct 12th, 2018, 23:17 | #46 |
Trader Volvo in my veins
Last Online: Yesterday 20:52
Join Date: Dec 2004
Location: Anglesey
|
Most 240 speedos read 5-10% fast
For snow a narrow is best as explained about but for all other conditions a wider tyre is better |
The Following User Says Thank You to classicswede For This Useful Post: |
Oct 12th, 2018, 23:22 | #47 | |
Premier Member
Last Online: Yesterday 23:53
Join Date: May 2012
Location: Lakenheath
|
Quote:
__________________
Cheers Dave Next Door to Top-Gun with a Honda CR-V & S Type Jag Volvo gone but not forgotten........ |
|
Oct 12th, 2018, 23:28 | #49 | |
Premier Member
Last Online: Yesterday 23:53
Join Date: May 2012
Location: Lakenheath
|
Quote:
Out of those, i've only checked the speedos on a few of them against either sat-navs or GPS mobile speedo apps. If you think they're from anunscientific source, download the app and do your own checks, i don't talk cowshed confetti, i've been an engineer all my life so there is no need, if it doesn't work then it doesn't work - simples. No need to dress up the facts as something they're not, enhance, embellish or otherwise. I had already advised you of the app i had used and invited you to download it and do your own checks, you then proceed to extract the urine. Get your facts right first!
__________________
Cheers Dave Next Door to Top-Gun with a Honda CR-V & S Type Jag Volvo gone but not forgotten........ |
|
Oct 12th, 2018, 23:35 | #50 |
Premier Member
Last Online: Oct 26th, 2023 20:42
Join Date: Jun 2010
Location: Thurrock
|
1985? Oh yes there was heavy snow about then one night lasting in to the next day. I had a broken windscreen in the beginning of that flurry. Most cars seemed to get around OK. Where I was.
Anyways. Thank you for reminding me about tall and skinny. (Sounds like a modern coffee.) That could tip a decision between different tyre sizes. My guess is. If a car maker specifies tall and skinny, that's a bonus in snow. Most makers specify a tad wider which as Dai says is better when there is no snow. Work out what is best for oneself. . Last edited by Stephen Edwin; Oct 12th, 2018 at 23:39. |
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests) | |
|
|