This has driven me crazy for the last 2 years...whenever I am at highway speeds (60-75) and have the cruise set, when let's say reaching a point of being about â…” down a long grade, my LR always downshifts or more accurately, unlocks the torque converter. Why?
This kills my mpg on runs thru hilly country with the downshifting and subsequent long drawn out wait to shift back to 6th. I've found that if I drive by foot, keeping a more steady control of the accelerator, the torque converter doesn't unlock nearly as much and I am able to post so much better mpg figures.
So what is it that causes my LR to unlock the torque converter at highway speeds when either going down a slope or when letting up on the accelerator at highway speeds?LR -- 2005 LR3 -- Zambezi Sliver
JR -- 2002 Range Rover HSE -- Zambezi Silver
Vandy -- 1999 Jaguar XJ8 VDP -- Mistral Metallic (now has a new home)
Blue - 2006 Audi A6 Quattro 4.2 -- Pearl Midnight Blue
20th Feb 2014 6:29 pm
wvlenthe
Member Since: 07 Jan 2009
Location: Arnhem
Posts: 1967
Mine does this too. I have always thought it is keeping the desired speed by shifting down (engine braking)? Thought of it as clever...
WiljoD3 V8 HSE Auto in Zermatt silver - driveway version gone but not forgotten, only the living room cupboard version remains
20th Feb 2014 8:48 pm
DiscoJake
Member Since: 23 Aug 2013
Location: Hereford
Posts: 1429
I thought you could stick it into 'command shift' so it doesn't do this?
Mine does this too. I have always thought it is keeping the desired speed by shifting down (engine braking)? Thought of it as clever...
Wiljo
That is also what I have thought...and what I've told who have ridden with me, when asked.
Never-the-less, it's annoying...and inefficient. Backing off the throttle should be sufficient enough...I believe.
BTW, in some instances it also appears that the LR also lightly applies the brakes to maintain an acceptable range within the set speed when using the cruise control. Anybody else witness this or have a knowledge of how the system works?
After all this time, I'm finally inquiring because I was wondering if perhaps the "feature" was included in an initial software revision...perhaps one that has since been updated to be "more efficient"?
BTW, good idea DJ. I'm going to give that a try next road trip to see our son at college.LR -- 2005 LR3 -- Zambezi Sliver
JR -- 2002 Range Rover HSE -- Zambezi Silver
Vandy -- 1999 Jaguar XJ8 VDP -- Mistral Metallic (now has a new home)
Blue - 2006 Audi A6 Quattro 4.2 -- Pearl Midnight Blue
21st Feb 2014 1:04 am
Colin hughes
Member Since: 17 Jul 2013
Location: Cannington, Ontario
Posts: 120
I've been messing with the cruise control over the last few days. It applies brakes going downhill and downshifts to fourth on big up hills. I've been playing with turning the cruise on and off on big down and up hills so I can coast down and control the downshifts a bit more going up. We'll see if it helps.
Because I've made several trips from San Antonio to Austin or to Waco (85 miles and 185 miles, respectively) I've had the opportunity to drive the routes many times using the cruise control and manually. The routes have many long stretched out hills. Not the mountain climbs one will find in the Rocky Mountain or other mountain states, but some pretty good size hills along the base of the Texas Hill Country region.
From my experience, if I drive the vehicle and maintain a fairly stable pedal, my mpg figures can vary as much as 4-6 miles per gallon. A huge difference. I'm convinced a large part of the difference is a result of the vehicle failing to immediately shift back into high (torque converter lockup) as soon as or immediately after I reach the peak of the hill. To make the vehicle shift back into high sooner when using CC, I've started lightly pressing on the peddle then letting up...causing the transmission to shift to high (6th).
Consider this...I was returning from a job across the city and it was a nice day so I popped the top and cruised along at 60 mph, driving manually. I had reset the meter and to my astonishment, I registered 25.3 mpg for the trip when I arrived at my drive. Two days later under similar if not the exact same conditions, I drove the same route at the same speed using cruise control...and registered 20.1 mpg upon arrival. The constant kick downs and delays in returning to 6th gear are what I am certain made the difference.
Take into account my wife's '06 Audi A6 Quattro with the 4.2...cruises thru all the same hills without downshifting and registering 26-28+ mpg at 70-75 mph. Granted, the LR is much larger, heavier and is like cutting butter with the broadside of the knife in comparison when it comes to aerodynamics...but, you'd think the 4.4 Jag engine would have enough torque to carry it over these hills (unloaded, 2 people) without the need to shift down.LR -- 2005 LR3 -- Zambezi Sliver
JR -- 2002 Range Rover HSE -- Zambezi Silver
Vandy -- 1999 Jaguar XJ8 VDP -- Mistral Metallic (now has a new home)
Blue - 2006 Audi A6 Quattro 4.2 -- Pearl Midnight Blue
21st Feb 2014 5:42 am
Colin hughes
Member Since: 17 Jul 2013
Location: Cannington, Ontario
Posts: 120
You are right about it wanting to hold the downshift. When I drive without CC and go up a hill, normally, it drops to 5th gear as I control the gas, with CC it drops to 4th and revs very high. I do find it likes to stay in 5th gear too unless I release the gas pedal and put my foot down again. I've only had the LR3 for about 5-6 weeks now and it's been unusually cold here in eastern Canada this winter with lots of snow and bad driving conditions so I'm looking forward to warmer weather when I can see how it performs.
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