Thread: New defender order

You are correct, most ATs will immediate add 0.5-1 litre per hundred.

I just put my 20's back on my Discovery 4 with 100% road tyres. I also took my Roof Rack of and I picked 3-4L / 100 improvement.

Originally Posted by jb007

I also wonder if All Terrain tyres reduce the economy as all the Defenders I have seen so far (only 5) had All Terrain tyres fitted.
Perhaps the All Season tyres are better option for on-road (urban and highway) driving!

mine is fitted with 18” Tuff Ant simpson alloys and Falken Wildpeak AT3W 275/65R18, I had the rear brake caliper
conversion with the ADR certification. Aussie P400’s come with the Goodyear AT adventures unless you ask
your dealer to change to all seasons

I went for a short test drive of the P400 S today - only got about 10 mins as the dealer had an appointment with another customer for a pickup.
But I will go for a longer test drive next week.

The test drive was very interesting and different to what I would have expected - when I applied the accelerator after stopping at red lights, there was a bit of a turbo lag (even with start/stop turned off), the power kicked in and the vehicle took off like a rocket! But once I got moving, the power delivery was very smooth to maintain the speed.

I wonder if this is an issue with the specific vehicle I test drove as it was a 2020 model - perhaps it was trashed around a bit or is this the way the power is delivered on P400 engine? Is this an issue during start-stop traffic?

Note - this may be because I am used to driving a diesel SUV and I am used to its power delivery.

Sounds like every car these days with electronic throttles where the computer decides you can’t possibly want to accelerate that fast. I doubt it’s turbo lag, but progressive throttle application buy the ECU

No delay on acceleration on ours, the electric supercharger element should minimise any turbo
delay by moving the P400 at a reasonable rapid rate

There was no lag in the P400 I drove. Where I did find the D300 a bit doughy.

I went for an extended test drive (30 mins) on both the P400 and D300 today in various conditions - mainly in start/stop Sydney traffic with a bit of freeway and a bit of hilly roads and I have come to the conclusion that both engines are great (I would pick any of them to be honest) and the difference comes down to how they are driven (in addition to the obvious petrol vs diesel differences).

As I mentioned in previous post, I have been driving Diesel vehicles for last decade and my "muscle memory" has developed to drive Diesel SUVs as follows:
- when the light goes green: let go of the brake and press the accelerator, feel the lag for like 0.5 seconds, and then gradually keep pressing the accelerator. My definition of "gradual" comes from my pilots training and the throttle is applied as: 10%,20%,30%......
- when driving in slow moving traffic, keep enough gap from the car in front to use engine braking (to some extent) to maintain the speed and gap
- when accelerating or going uphill, again, don't just smash the accelerator pedal but feel the gradual pull / torque provided by the Diesel engines to get moving and reach the desired speeds

In summary, everything happens in a controlled, gradual, steady and linear way - some may call this "mushy" way!

This is exactly how I drove the D300 and felt more comfortable as I am used to driving this way. I also noticed that the transmission in the D300 was not changing gears that often - again as expected from a Diesel engine with plenty of torque down the rev range.


When I drove the P400 the first time around, I was trying to drive it in a similar way which was not ideal so, this time around, I changed my driving style to be a bit more "engaged", "active" and "commanding". For example,
- when taking off the lights, applying the throttle slightly more aggressively - I don't mean smash the pedal to the floor but rather aim for power application as: 25%, 50%, 75%,... This worked really well and got rid of the "lag" I experienced the first time around
- maintaining constant speed was interesting and I felt that it required a bit of work (over the D300) as the engine had very little engine braking so I had to use my right foot a bit more with constant applications of the brake and accelerator pedals to maintain the gap and speed
- driving on the highway and going uphill was so easy on the P400 and the vehicle effortlessly got upto speed and maintained the speed

I did notice that the transmission was changing more gears than the D300 to stay on the power curve - as expected from the Petrol engines.


Based on this experience, as I mentioned earlier, both the engines are great and need to be driven accordingly.
I think after couple of days, I can get used to driving the P400 and all the lag I experienced on the P400 during my first test drive was down to the way I was driving and not the engine.