Hill climbing and gearing

[dg]

Just came back from Exmoor where I first time experienced 25% gradients 
I felt like car is barely moving uphill in 2nd gear(cars queuing behind) whereas in 1st it's over-revving. maybe  I'm doing something wrong..

As for prolonged downhill, in 2nd gear it was reaching 4.5k easily. What is the safe rpm here? is it ok not to use brakes till 5-6k? Is it ok to engage 1st gear on steep downhill?

[guest2765]

relevant to my interests too...tbh the car is fine if its already moving...3rd and 4th work for uphills on dual carriageways but for the hill beside newbyth a village where my friend stays...i get land rovers, and other 4x4's at the back of me as my jazz struggles up the 25-30% gradient hill in 2nd... outside a village called strichen as well i sit going up the hill at 30mph (ok so its a sharpish uphill bend and 40 would probably be my max going up as it is going down the hill) but my car struggles unless in 1st or 2nd up this hill, so i dont recon your doing anything wrong, maybe just the way the gears are done as the jazz is meant to be economical etc dont think they thought out the hill climbing part of things.. (interested in anyone elses replies)

[guest3040]

After reading this earlier i decided to test out my gearing on the way home...
I found the gearing between 1st and 2nd to be quite far apart. Revving all the way to 6000 rpm in first gear would give me less than 4000 rpm in 2nd, so i can imagine it bogging down when going up a steep incline.

[culzean]

either your brakes are stuck on,  you have the boot full of wet sand or you are using supermarket petrol -

 Never had a problem with hills in Devon and Cornwall (or anywhere else for that matter) and certainly wouldn't expect to see a Jazz in front of the queue - My Jazz (GD 1.4) goes up hills better than my previous Civic VTEC, which didn't have much pull below about 2500 rpm. 

Is your Jazz a GD or GE model.  Jazz GD is actually pretty low geared (21mph per 1000 rpm in 5th) compared to the Civic which was about 28mph/1000 in 5th. And Jazz gears are pretty close together

[Pine]

Get yourself a Jazz with CVT. Brilliant for climbing hills, always in the right gear.

[guest2765]

either your brakes are stuck on,  you have the boot full of wet sand or you are using supermarket petrol -

 Never had a problem with hills in Devon and Cornwall (or anywhere else for that matter) and certainly wouldn't expect to see a Jazz in front of the queue - My Jazz (GD 1.4) goes up hills better than my previous Civic VTEC, which didn't have much pull below about 2500 rpm. 

Is your Jazz a GD or GE model.  Jazz GD is actually pretty low geared (21mph per 1000 rpm in 5th) compared to the Civic which was about 28mph/1000 in 5th. And Jazz gears are pretty close together

Ive got a GD 1.4... and it does struggle with the higher gradient hills (dont get me wrong if i want to park on them then its no problem) and this has happened while not carrying anything in the boot, not having the brakes on at all (as the car was recently serviced and put on a diagnostics machine this would have been highlighted). Im not sure if you are trying 25% gradient hills? I know i normally dont have a problem climbing hills, does for me seem to be if im coming out of a village at 30 climbing hills is a painfully slow for acceleration, fine enough moving about in towns and cities.

[dg]

either your brakes are stuck on,  you have the boot full of wet sand or you are using supermarket petrol -
Is your Jazz a GD or GE model.  Jazz GD is actually pretty low geared (21mph per 1000 rpm in 5th) compared to the Civic which was about 28mph/1000 in 5th. And Jazz gears are pretty close together

brakes are fine and no load, only 130kg of humans and 30kg in the boot
was using some no-name fuel, filled up on motorway, not sure if it makes that big difference but will definitely try high octane next time out
Jazz is 1.4 GD

Get yourself a Jazz with CVT. Brilliant for climbing hills, always in the right gear.

he he no, thanks. I'll better spend some time learning In 10-20 years we might find ourselves in electrocars with no gearboxes at all, need to enjoy now 

What about 1st gear downhill? and safe RPMs while using engine braking?
BTW, does GD's ECU shut off fuel supply in this case?

[guest2765]

Get yourself a Jazz with CVT. Brilliant for climbing hills, always in the right gear.

he he no, thanks. I'll better spend some time learning In 10-20 years we might find ourselves in electrocars with no gearboxes at all, need to enjoy now 

What about 1st gear downhill? and safe RPMs while using engine braking?
BTW, does GD's ECU shut off fuel supply in this case?

haha nah in 10-20 years ill still be driving a petrol (or diesel if needsbe) with a gearbox..haha oil in the north sea still has 40+ years left nevermind the rest of the world

not sure about first gear downhill, i stick to 2nd or 3rd, depends on the gradient and how fast you are going though.

[guest1521]

GRDMITRO... 3500rpm to 5000rpm through gears on steep uphill works well for my 1.2 GE. Its powerband is in that area.  Fall below those revs and it can feel breathless. For a GD, torque builds and peaks at lower revs, however... I think. 

DOWNHILL I use my lower gears a lot for engine braking. Rather than 'whack it down' the gearbox, I brake momentarily as I change down which, I hope, eases mechanical stress through the transmission. Smooth braking timed with the (gentle) downchange also helps maintain overall balance of the car and so, I hope, helps maintain grip on all four tyres.  (Brakes discs and pads are more expensive to maintain in these post-asbestos pads days.) However I then will use the brakes a little to stop it revving its head off...  first gear engine brake if necessary, too. Lorry driving years ago with heavy, unstable loads taught me these habits - whether they are good or not so good. And lots of fast driving on gravel roads.

Apologies... having posted I realised yours is a GD. However the gist of it must be about the same, I think.

[dg]

... However I then will use the brakes a little to stop it revving its head off...  first gear engine brake if necessary, too.

Thanks! that what I wanted to confirm.

I was taught to avoid high RPMs and to minimize usage of low gears some years back learning to drive Ford Sierra, now sound of continuously revving engine(uphill or downhill) worries me, although I understand it's should be fine while it's below red line. (my father burned piston rings once after prolonged 1/2 gear offroad struggles)

[guest3250]

Torque is high up the rev band - and despite the engine being smooth and economical low down - you won't have a lot of grunt
Keep the revs between around 4000 and 6000 going up very steep hills and it should be OK
I am new to this and would prefer the torque lower down - but I guess you can't have everything!!