A gear ratio is calculated by dividing the output by the input. A low gear (e.g. first gear) has a high ratio, a high gear (e.g. sixth gear) has a low ratio. Reverse gear is pretty much always a lower ratio than first gear, and so it will be easier for the car to roll in reverse gear.Smartbear said:wonkydonkey said:First gear has a higher ratio than reverse, so your car is more likely to roll down a hill if you leave it in reverse rather than in first. Just a little FYIskelters said:
It’s the opposite way round, it’s easier to push a car along in a higher gear than a lower one
Rob
Parking on a slope
- Thread starter Whiterhino114
- Start date
It can, yes. Our engines are capable of rotating in either directionenzed4 said:Are you saying the car can roll forward when in reverse gear? I didn't think that was possible :?wonkydonkey said:First gear has a higher ratio than reverse, so your car is more likely to roll down a hill if you leave it in reverse rather than in first. Just a little FYIskelters said:
[ref]skelters[/ref] I'm not saying you have to choose between engineering fact and advice published by motoring bodies. The decision is all yours
wonkydonkey said:[ref]skelters[/ref] I'm not saying you have to choose between engineering fact and advice published by motoring bodies. The decision is all yours
I've been driving for about 30 years and this is the first I've ever heard of parking in 1st gear when facing down a hill.
But the self proclaimed, "experts" on here know better than the motoring bodies!
Attleborough, Norfolk
I've spoken to plenty of guys who have been driving for decades who furiously state that all wheel stud/wheel bolt threads should be greased as well, because it's what they've always done and what they've always been told to do. They dismiss explanations of the risk of shearing them off due to excessive preloading because it's different to what their dad said. Old habits are often a good rule of thumb, but that doesn't mean that they are superior to factsskelters said:wonkydonkey said:[ref]skelters[/ref] I'm not saying you have to choose between engineering fact and advice published by motoring bodies. The decision is all yours
I've been driving for about 30 years and this is the first I've ever heard of parking in 1st gear when facing down a hill.
But the self proclaimed, "experts" on here know better than the motoring bodies!
sars said:buzyg said:Scarey lot. :lol:sars said:Completely unrelated, in Germany it’s a legal requirement to have the wheels pointed into the kerb when parking on a hill
For too sensible and pragmatic those Jerry's. :wink:
I had some German colleagues visiting and one noticed a car parked on a hill, facing down hill (thanks enzed), with the wheels pointed away from the kerb and he was horrified, to the extent that it was like I’d asked him to choose which child :!:
wonkydonkey said:I've spoken to plenty of guys who have been driving for decades who furiously state that all wheel stud/wheel bolt threads should be greased as well, because it's what they've always done and what they've always been told to do. They dismiss explanations of the risk of shearing them off due to excessive preloading because it's different to what their dad said. Old habits are often a good rule of thumb, but that doesn't mean that they are superior to factsskelters said:wonkydonkey said:[ref]skelters[/ref] I'm not saying you have to choose between engineering fact and advice published by motoring bodies. The decision is all yours
I've been driving for about 30 years and this is the first I've ever heard of parking in 1st gear when facing down a hill.
But the self proclaimed, "experts" on here know better than the motoring bodies!
Not arguing, it’s just that statement is a little rich, I was taught to put the car in gear when on an incline because back in the day handbrakes were pretty crap and unreliable (think Morris marina). Handbrakes are very much less likely to fail these days than thirty or forty years ago in the same way that nuts on modern vehicles are corrosion resistant.
Leaving a car in gear is certainly a good way to reduce the risk of it rolling away. I agree with that. I think some debate has sparked up because I pointed out that first gear has a higher ratio than any other gear in most gearboxes (including our Z4s), which makes first gear the best gear to resist the pull of gravity if you've parked on a slopesars said:
wonkydonkey said:Leaving a car in gear is certainly a good way to reduce the risk of it rolling away. I agree with that. I think some debate has sparked up because I pointed out that first gear has a higher ratio than any other gear in most gearboxes (including our Z4s), which makes first gear the best gear to resist the pull of gravity if you've parked on a slopesars said:
It’s my fault, i confused your statement with high/low gears and ignored the ratio bit
Rob
I was a lecturer in motorsport engineering at one point in my career. Gear ratios and crown wheel pinion ratios would inevitably trip a few people up in the room on any one day...including me every now and then! Easily doneSmartbear said:It’s my fault, i confused your statement with high/low gears and ignored the ratio bit
Rob
I still can't get my head around the idea that a car is more likely to roll down hill (facing down hill, not facing up the hill) when in reverse gear than in first gear. Learn something every day :lol: . Does that mean, by the same token, it would be easier to push a car backwards in 6th gear than it would in 1st gear (because 6th is a lower ratio than 1st)?wonkydonkey said:I was a lecturer in motorsport engineering at one point in my career. Gear ratios and crown wheel pinion ratios would inevitably trip a few people up in the room on any one day...including me every now and then! Easily doneSmartbear said:It’s my fault, i confused your statement with high/low gears and ignored the ratio bit
Rob
Yep! Try it on your carenzed4 said:
With the engine off and the car on the level, stick it in sixth gear and you'll be able to nudge the car backwards or forwards fairly easily.FYI the ratios are listed online as 4.35 (first gear) and 3.93 (reverse gear), so there's about a 10% difference between them.
I've found a light-hearted chat about it. The ending cracked me up :lol:
https://www.cartalk.com/content/will-putting-vehicle-reverse-guarantee-it-wont-roll-down-hill
https://www.cartalk.com/content/will-putting-vehicle-reverse-guarantee-it-wont-roll-down-hill
Can't test that with my DCT but I'll take your word for itwonkydonkey said:Yep! Try it on your carenzed4 said:
FYI the ratios are listed online as 4.35 (first gear) and 3.93 (reverse gear), so there's about a 10% difference between them.
No-one likes a show-offenzed4 said:Can't test that with my DCT but I'll take your word for it
[ref]enzed4[/ref] that's the main thing! 