This was one of the first threads I followed when I started "lurking" around on the forum. I liked what I saw on the forum so registered in October last year. I've posted on a few other subjects and had very positive reaction and advice so thought I'd toss in my ha'penny worth on this subject.
I started driving, on private estate land, back in the '50s in my early teens. Tractors, - a red David Brown and a "little grey Fergie" 1930 Morris Minor, 1935 Morris 8, and the estate Austin pickup. None of these vehicles were well maintained - they were only driven on private land - so if you didn't leave them parked in gear they often weren't where you left them next time you went back! I got in the habit of leaving vehicles in 1st gear when parked. When I was then taught to drive on the road, my instructor, the redoubtable Mr Scott, was very keen on you always "waggling" the gear lever to check neutral was selected before starting up, so being in gear on start up has never been a problem for me.
When I later trained as a mechanic I learned how to properly adjust handbrakes so my opinion now is that there should be no need to leave the car in gear, just apply the handbrake. I agree with "Portland Bill" that the hand brake should be pulled up with the button depressed only releasing the button to allow it to engage with the pawl teeth when it is fully applied. ie. Don't "rake" it up over the teeth as they can suffer abnormally rapid wear. After you've applied it a wee pull up on the lever with no pressure applied to the button can act to reassure you that the pawl is properly engaged. Electric hand brakes? WHY? I really don't want to even think about them!
One of the reasons for leaving in gear is often given as extra security when parking on steep hills. The theory is that engine compression will stop the car moving. If you think about this for a minute it's obvious this can't work. No engine has perfectly sealing pistons so as the turning force on the crankshaft tries to force the piston up it's bore the resisting air will, albeit slowly, leak past the piston rings and, if you're unlucky, the valve seats, and the engine will turn. Turning the steering so that the tyre jams against the curb works well but may not be that good for the tyre on very steep hills. By the way, if you are going to leave it in gear, then I strongly agree that you should not engage a gear which which might cause the engine to turn backwards. Overhead cam drives use quite long chains or synchronous belts. The chances of introducing enough slack into this train by turning the engine backwards, especially with chain drives, to cause the chain to jump teeth on the sprockets is significant. So, if you're facing downhill engage 1st gear, if facing uphill it's got to be reverse. To this day I carry a set of wheel chocks in the boot for added stability if I have to change a wheel. I would deploy these for extra security if I had to leave the car for any length of time on a steep hill.
A few more thoughts before I leave you.
# Counting "clicks" is pointless as there are fine and course ratchets
# There may be a potential danger with leaving a "stop/start" equipment vehicle in gear. A malfunction might cause the starter to kick over the engine with disastrous results. I have a vague recollection of this being a problem with one of the early versions. My daily driver has stop/start (which I dislike) so I never leave it in gear.
# With regard to depressing the clutch pedal when starting, I have mixed feelings. I hear what people say about gearbox oil drag and that by depressing the clutch you loose that. I've never found much advantage in this except perhaps in really freezing weather and modern gear oil is now so "thin" that it is even less of a problem. But I do worry about the crankshaft thrust washers. Have a think about this. When you depress the clutch pedal the clutch release bearing pushes against the thrust face on the clutch diaphragm and compresses it. This diaphragm is a VERY powerful spring, put one flat on the ground and you won't compress it even if you jump up and down on it! The clutch is mounted on the flywheel of the engine which is itself bolted to the end of the crankshaft. So, when you push down on the clutch pedal and compress the clutch diaphragm you are applying a very significant axial force to the crankshaft. You are in effect, trying to push the crankshaft out of the front of the engine! What is resisting this? On most engines, A couple of small, half moon shaped, thrust washers! When the engine is running there is a good supply of oil from the crank journal to protect them but there is little oil for them until the oil pump is feeding oil after start up so I don't like to start an engine with my foot down on the clutch pedal! Triumph 2000's were particularly vulnerable and often turned up in the workshop with stalling problems due to so much end float on the crank that it was trying to mill it's way out of the front of the engine!. I'm well aware that the latest generation of vehicles now have a switch on the clutch pedal (my daily driver is one) which require the clutch to be depressed before the starter will operate so I assume this issue of thrust bearing lubrication has been addressed but so far no one at my dealer has been able to give me an informed explanation! A further discouragement for me to keep my foot off the clutch was that when I learned to drive clutch release bearings were carbon thrusts, no fancy ball races! Sitting with your foot down on the clutch pedal would lead, very quickly, to the demise of the thrust bearing!
Well, that's quite enough of me rambling on for tonight. The aliens are about to put in an appearance so I need to go to bed with my book!
Stay safe everyone
Jock