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I hesitate to use firmed up suspension unless I'm sure the road is in decent condition. There are so many potholes this time of year and on the normal soft setting the 20" wheel stands a chance of taking the punch whereas on firm it might take a ding or hurt the tyre before the impact is absorbed.
 

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What's Eco? 馃榿馃榿
How dare you. I've spent 拢180 on powering my electric vehicle over the past 14,000 miles!

My arms don't need to reach the steering wheel if I use Autopilot.
 
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I鈥檝e spent more money fuelling my R-S than I have charging the I-PACE even though I鈥檝e done at least twice the mileage.

I鈥檝e also spent more money fuelling the Disco in the last 4 weeks than I have charging the I-PACE in the last year.


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$Money can't buy you love!$
 
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Just a couple of points about diesels.
In diesel engines, there is no engine braking and coasting or going downhill in N would not make any difference to use D. Please do not use lower gears in downhill, you are putting stress on plastic parts in air induction system
Using S for gearbox makes a big difference for me because it downshifts faster and sticks to lower gears mostly due to higher torque. It feels like an electric car without gearbox in that speed range. It also feels like a manual transmission. Changing gears are also quicker.
It also selects a gear that is ready for acceleration even if you are coasting.
e.g. if I am coasting at 30mph in D, it would pick 6 or 7. If I switch to S, it will pick 3 to keep engine around 3000rpm ready for going flat.
 

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Just a couple of points about diesels.
In diesel engines, there is no engine braking and coasting or going downhill in N would not make any difference to use D. Please do not use lower gears in downhill, you are putting stress on plastic parts in air induction system
Using S for gearbox makes a big difference for me because it downshifts faster and sticks to lower gears mostly due to higher torque. It feels like an electric car without gearbox in that speed range. It also feels like a manual transmission. Changing gears are also quicker.
It also selects a gear that is ready for acceleration even if you are coasting.
e.g. if I am coasting at 30mph in D, it would pick 6 or 7. If I switch to S, it will pick 3 to keep engine around 3000rpm ready for going flat.
Sorry, are you talking about driving a diesel engined car here? Of course there is engine braking in D going downhill, air is still drawn into the engine and compressed, same as if the throttle were open, just no, or little fuel is injected. No idea what you're on about additional stress to plastic induction parts! Putting the car into N and coasting downhill is also dangerous, not to mention technically illegal (not being in full control of a vehicle). Putting the gearbox into S setting (at least on my 3.0D) causes up-changes at the engine red line which is totally pointless and then the next gear is already at the upper limit of the torque band, really need to be up-shifting at 3.5k max, not 4.5k.
 

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I put it in D and press the accelerator pedal. Occasionally I press the brake pedal.
 

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Sorry, are you talking about driving a diesel engined car here? Of course there is engine braking in D going downhill, air is still drawn into the engine and compressed, same as if the throttle were open, just no, or little fuel is injected. No idea what you're on about additional stress to plastic induction parts! Putting the car into N and coasting downhill is also dangerous, not to mention technically illegal (not being in full control of a vehicle). Putting the gearbox into S setting (at least on my 3.0D) causes up-changes at the engine red line which is totally pointless and then the next gear is already at the upper limit of the torque band, really need to be up-shifting at 3.5k max, not 4.5k.
Yes. I know it is confusing but other than engine parts friction that is next to nothing, there is no engine braking in a passenger diesel car by its nature. There are extra systems they install on diesel trucks to replicate engine braking.
There is no throttle body in a Diesel engine like a petrol that controls air flow to control engine speed. There is a shutoff valve actuator that always fully open until you want to stop engine when it shuts. Engine speed changes only by frequency of fuel injection. You cannot restrict the amount of air going to engine when you release the gas pedal. Air goes in an out. Compression force minus friction is cancelled out by expansion.
when you intentionally use a lower gear going downhill, you are only using the restrictions caused by turbo ( when exhaust and intake have a similar flow rate) and other traps in air intake for keeping engine speed down which puts stress on all those plastics that are designed for positive pressures. If you notice, engine braking only works when engine rpm is above 3000. Pressure drop in air intake is exponentially related to air flow. In many diesel car鈥檚 handbooks it is mentioned not to use this technique.
Coasting downhill in N is not good because transmission鈥檚 oil pump is connected to input shaft. It will overheat in N at higher speeds. Diesel has a vacuum pump and brakes should be fine in N unlike most petrols that use intake manifold vacuum which is much less at ideal speed when coasting in N.

Re gearbox behaviour, I think it is still beneficial to use S because although it won鈥檛 help with keeping engine at it鈥檚 most powerful state, it helps with the torque available at the wheels and their speed. Mine changes gear as low as 3200 in S if I am light on throttle. But you know these gearboxes adopt to drivers way of driving.
 

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How do you explain the fact that a BMW diesel has considerable engine braking in Drive, but if ECO is selected the gearbox decouples & there is virtually no retardation?
 

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Yes. I know it is confusing....

Compression force minus friction is cancelled out by expansion.

.....use a lower gear going downhill, you are only using the restrictions caused by turbo ( when exhaust and intake have a similar flow rate) and other traps in air intake for keeping engine speed down which puts stress on all those plastics that are designed for positive pressures.

Diesel has a vacuum pump and brakes should be fine in N unlike most petrols that use intake manifold vacuum which is much less at ideal speed when coasting in N.
Hmm. Hamed, I think you need to revisit your knowledge of engines and engine systems, especially how you believe modern diesels work.

"Yes. I know it is confusing" - No, I'm not confused.

"Compression force minus friction is cancelled out by expansion" is a nonsensical expression, what expansion are you referring to here? If you're referring to air compression in the cylinder, then the kinetic energy of the car turning the engine has already been used to compress the air and change it to heat energy, the expansion of the air as the piston moves down does not cancel out the previous compression as the energy conversion has already been done, time has moved forwards etc.

"restrictions caused by turbo" What restriction, while the engine is in over-run? There will be only sight air restriction through the turbo as the air is exhausted from the engine, and in any case this restriction would in theory only add to the engine braking as the pistons try to push the air out through the open exhaust valve into the exhaust system and past the turbo, which will be spinning slowly. Very likely no restrictions at all to the moving air mass and no measurable engine braking to be gained.

"stress on all those plastics that are designed for positive pressures. " You are saying that the intake is under negative pressure here, but there is very little vacuum in a diesel intake system, hence the vacuum pump you later mention. I have never come across a diesel intake system damaged by implosion. Overpressure explosion, yes, and the 3.0D is well known for this.

"brakes should be fine in N" - No! The brake system will work just fine in neutral in a diesel, due to the vacuum pump ensuring the brake booster stays functional, but there is the high probability of overheated brakes and so brake failure if no engine braking is used, which you're saying is either non-existant or at least shouldn't be used in a diesel and protracted downhill driving is done. You may drive in front of me please if we're in the Alps, I wouldn't want you behind me going down the mountain roads not using any engine braking and only relying on the foot brake!

I'm not purposely wanting to contradict you, however saying there is no engine braking in a diesel car and that drivers shouldn't drive a diesel car in a low gear downhill is plain wrong and potentially dangerous.
 
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How do you explain the fact that a BMW diesel has considerable engine braking in Drive, but if ECO is selected the gearbox decouples & there is virtually no retardation?
Unless they made intake of aluminium and purposely use shut off valve to make a similar effect, it鈥檚 just friction. There is virtually no engine breaking in my XFS for sure. If you downshift to have 3-4k rpm you feel some but that is a lot of stress on intake manifold.
 

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Hmm. Hamed, I think you need to revisit your knowledge of engines and engine systems, especially how you believe modern diesels work.

"Yes. I know it is confusing" - No, I'm not confused.

"Compression force minus friction is cancelled out by expansion" is a nonsensical expression, what expansion are you referring to here? If you're referring to air compression in the cylinder, then the kinetic energy of the car turning the engine has already been used to compress the air and change it to heat energy, the expansion of the air as the piston moves down does not cancel out the previous compression as the energy conversion has already been done, time has moved forwards etc.

"restrictions caused by turbo" What restriction, while the engine is in over-run? There will be only sight air restriction through the turbo as the air is exhausted from the engine, and in any case this restriction would in theory only add to the engine braking as the pistons try to push the air out through the open exhaust valve into the exhaust system and past the turbo, which will be spinning slowly. Very likely no restrictions at all to the moving air mass and no measurable engine braking to be gained.

"stress on all those plastics that are designed for positive pressures. " You are saying that the intake is under negative pressure here, but there is very little vacuum in a diesel intake system, hence the vacuum pump you later mention. I have never come across a diesel intake system damaged by implosion. Overpressure explosion, yes, and the 3.0D is well known for this.

"brakes should be fine in N" - No! The brake system will work just fine in neutral in a diesel, due to the vacuum pump ensuring the brake booster stays functional, but there is the high probability of overheated brakes and so brake failure if engine braking, which you're saying is either non-existant or at least shouldn't be used in a diesel and protracted downhill driving is done. You may drive in front of me please if we're in the Alps, I wouldn't want you behind me going down the mountain roads not using any engine braking and only relying on the foot brake!

I'm not purposely wanting to contradict you, however saying there is no engine braking in a diesel car and that drivers shouldn't drive a diesel car in a low gear downhill is plain wrong and potentially dangerous.
It鈥檚 just discussion but I have been reading a lot about this to see why my intake manifold cracked. See article below under diesel engine.

Jaguar鈥檚 3.0D is not designed to do engine braking and it will put stress on engine. Let alone it鈥檚 not good idea for gearbox.
 

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I'm very likely changing my 3.0 diesel XFS for a 3.0 petrol supercharged F-Pace soon, that will most definitely have engine braking! 馃榿
 
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I'm very likely changing my 3.0 diesel XFS for a 3.0 petrol supercharged F-Pace soon, that will most definitely have engine braking! 馃榿
I am with you Alan馃槃. To be honest if there is one reason I switch to a petrol would be this lack of engine braking. There is a steep downhill next to our house and it鈥檚 reminded almost daily how much I miss this feature.
another video about this. My car at-least does not have neither of the features he discusses that could help with engine braking on a diesel.
 

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I'm interested to know how people drive their jags in different scenarios, I want to ensure I am driving best for the car and my enjoyment.

So I'll start:
City driving: Normal Mode

Dual Carriageway (short journey): combination of Normal Mode or Dynamic mode depending on if kids in car/ how busy road / weather conditions

Motorway driving (say 300 miles North to South): This is the one I a most unsure about with regards to the use of cruise control, eco mode, normal mode and dynamic mode
I was thinking a combination of:
1. Eco Mode with cruise control (average speed cameras)
2. Combination of Eco/ Norma/ Dynamic Mode (I had been informed by @JaguarDriver that Dynamic mode is best for the car)
Does dynamic mode use significantly more fuel than Eco or normal modes?
In all honest I'm really not sure what is best, or is the answer that a combination of modes is the best solution?

Fun: Dynamic and Sports mode

Happy driving
In a few days, hopefully quicker than V3, well off the lights anyway ;)

V3 has taught me that I'm a bit of a throttle tart. What will a XJR 575 teach me? (Aside from correct tyres, and careful in the wet!)
 

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An interesting discussion.
I, for one, never go down hill in neutral, or anywhere else for that matter.
 
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In Dynamic mode at all times regardless of weather or road conditions.
Set to Dynamic for throttle response, gearbox response and steering but Normal for suspension, I like the first three to be snappy and responsive at all times but not so much the suspension.
Careful with the go pedal in crap weather though.
 

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An interesting discussion.
I, for one, never go down hill in neutral, or anywhere else for that matter.
I dislike the way BMW decouples the transmission when you lift in ECO mode. The car feels like a runaway train... especially downhill.
 

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Some old Rovers used to do that
It's an odd feeling.
 
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