Radar cruise control-interestingly nice
#62
Exactly, once on the freeway I switch it on and don't touch it till I'm off the freeway (even then I'll leave it on as long as possible as I love how the car stops on it's own at lights, traffic, whatever).
#63
If the control logic is flawed, and DRCC is causing unusually harsh downshifts (which at certain speeds would result in RPMs moving up) then I`d suggest going into the dealership. Nothing really can be done if this is this is how Lexus intended its control logic to function, besides making them aware of the issue and hoping they issue a TSB. As a side note, anyone know what systems DRCC should control during a downhill event where speed would increase above set speed, constant distance vehicle in front?
I`d assume it`d be a mixture of engine downshifting with brake application?
I`d assume it`d be a mixture of engine downshifting with brake application?
And I would like to repeat what issue I am concern about. Only on those two occasions described above. On normal DRCC operations, the downshifting to come up to speed or accelerate is smooth as silk. Or that if you happen to follow a slower moving vehicle while on DRCC, it will actually apply the brakes to slow down and follow speed. Note, I did not mention engine braking in this instance for it does not. And if you happen to change lane to pass the said vehicle in front of you, DRCC will downshift smoothly as required to come back up to set speed. Or if you happen to hit a up slope road while on DRCC, it will smoothly downshift (as required) to accelerate to overcome the torque required to maintain set smooth. And finally, if you hit a downslope road, it will apply the brakes to slow down to set speed. Again, note I did not mention engine braking to maintain speed because it doesn't.
#64
Lead Lap
That doesn't work with the vehicles we own that have DRCC. If I try to accelerate and override the DRCC to get very close to a vehicle I want to pass on a winding, hilly 2-lane road, DRCC fights back and applies the brakes. I may have to "ride the bumper" of the vehicle in front of me for several minutes until it is clear to pass.
#65
That doesn't work with the vehicles we own that have DRCC. If I try to accelerate and override the DRCC to get very close to a vehicle I want to pass on a winding, hilly 2-lane road, DRCC fights back and applies the brakes. I may have to "ride the bumper" of the vehicle in front of me for several minutes until it is clear to pass.
not sure what you own, this topic is about the 4th gen 16+ rx350/450
Tested, no problem pulling up behind a car with the drcc set.
you could also test in your 4th gen RX and let us know you find.
Last edited by JSracer; 01-03-18 at 07:38 AM. Reason: Tested to work as originally posted with drcc set.
#66
no need to ride the bumper, but thats another conversation for another time.
not sure what you own, this topic is about the 4th gen 16+ rx350/450
Tested, no problem pulling up behind a car with the drcc set.
i will test again today to be %100 but i am sure i have gotten closer with stepping on the gas.
you could also test in your 4th gen RX and let us know you find.
not sure what you own, this topic is about the 4th gen 16+ rx350/450
Tested, no problem pulling up behind a car with the drcc set.
you could also test in your 4th gen RX and let us know you find.
#67
Lead Lap
Situations like this require you to be very close to the vehicle you are want to pass although maybe "riding the bumper" is not a term you like. The problem is that on a downhill stretch while following a vehicle closely, having your DRCC engaged even at the shortest following interval can cause your vehicle to brake and fall back from the vehicle you want to pass which increases your exposure time if you were to pull out to pass while too far back.
Maybe this is a situation that you rarely encounter or have never encountered. I fairly regularly drive what I call the "40 miles from hell" rural winding, hilly 2-lane blacktop road where I often have barely a few seconds to zoom around slower moving farm vehicles.
#68
Maybe I should give up trying to explain this but the problem with attempting to use DRCC on 2-lane hilly, winding rural including mountainous roads particularly arises on downhill stretches when you are waiting for a clear area to pass when you encounter adequate forward visibility on a clear road and no oncoming traffic. Passing sometimes has to be done extremely quickly before the opportunity has passed.
Situations like this require you to be very close to the vehicle you are want to pass although maybe "riding the bumper" is not a term you like. The problem is that on a downhill stretch while following a vehicle closely, having your DRCC engaged even at the shortest following interval can cause your vehicle to brake and fall back from the vehicle you want to pass which increases your exposure time if you were to pull out to pass while too far back.
Maybe this is a situation that you rarely encounter or have never encountered. I fairly regularly drive what I call the "40 miles from hell" rural winding, hilly 2-lane blacktop road where I often have barely a few seconds to zoom around slower moving farm vehicles.
Situations like this require you to be very close to the vehicle you are want to pass although maybe "riding the bumper" is not a term you like. The problem is that on a downhill stretch while following a vehicle closely, having your DRCC engaged even at the shortest following interval can cause your vehicle to brake and fall back from the vehicle you want to pass which increases your exposure time if you were to pull out to pass while too far back.
Maybe this is a situation that you rarely encounter or have never encountered. I fairly regularly drive what I call the "40 miles from hell" rural winding, hilly 2-lane blacktop road where I often have barely a few seconds to zoom around slower moving farm vehicles.
#69
Closely following the vehicle in front of you in anticipation of passing just increases the potential for an accident. Following too closely decreases your reaction time if the vehicle in front of you brakes unexpectedly. Combine this with your focus on finding a safe opportunity to pass and you will find it impossible to react in time.
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GSFRX350 (01-04-18)
#70
Wait, in driving condition like "rural winding, hilly 2-lane blacktop road where I often have barely a few seconds to zoom around", why can't you just turn off the cruise control for a few seconds?
#71
I believe we can now put this DRCC driving thing to rest. Bottom line is as the saying goes, "There are a million ways to skin a cat" And of course same holds true with driving. Just because you drive one specific way, doesn't mean it's the only way. And the same holds true with the use of cruise control. If you disengage your CC when passing, there is absolutely nothing wrong with that and of course, the same holds true if you just leave it engaged.
One thing that is not true is when you presume how the system will react based on its basic description. The 4RX DRCC will maintain set speed and distance to the car infront only if you leave it alone. As soon as you interfere with it like stepping on the gas, depending how much you press it, but as soon as the pressed gas pedal position is higher than the DRCC set speed, it will override the DRCC temporarily suspending it (the set speed and distance) until you let go of the gas pedal or decrease its pressed position (lower than that of the set speed). Then DRCC will resume its operation of maintaining set speed and distance. This is how you can close in the distance between you and the car infront without disengaging DRCC, temporarily. The same holds true with conventional CC except because it is not dynamic, it will only resume set speed but not distance from the car in front or ahead.
Some people presume that because the CC or DRCC is engaged that you cannot step on the gas to increase vehicle speed, or that you have to use the DRCC/CC stalk to increase speed temporarily and then use the stalk again to decrease speed, or to disengage (cancel) DRCC increase speed and then decrease and reset. Although, this can be done it can also be conveniently done by simply stepping on the gas and letting it go when you wish to go back to set speed.
One thing that is not true is when you presume how the system will react based on its basic description. The 4RX DRCC will maintain set speed and distance to the car infront only if you leave it alone. As soon as you interfere with it like stepping on the gas, depending how much you press it, but as soon as the pressed gas pedal position is higher than the DRCC set speed, it will override the DRCC temporarily suspending it (the set speed and distance) until you let go of the gas pedal or decrease its pressed position (lower than that of the set speed). Then DRCC will resume its operation of maintaining set speed and distance. This is how you can close in the distance between you and the car infront without disengaging DRCC, temporarily. The same holds true with conventional CC except because it is not dynamic, it will only resume set speed but not distance from the car in front or ahead.
Some people presume that because the CC or DRCC is engaged that you cannot step on the gas to increase vehicle speed, or that you have to use the DRCC/CC stalk to increase speed temporarily and then use the stalk again to decrease speed, or to disengage (cancel) DRCC increase speed and then decrease and reset. Although, this can be done it can also be conveniently done by simply stepping on the gas and letting it go when you wish to go back to set speed.
Last edited by Jiggz858; 01-04-18 at 10:15 AM.
#72
You absolutely can if you so prefer. But others like me normally do not disengage CC instead we just step on the gas and when the pass is complete I just let go and resume CC. It's a personal preference. There is nothing wrong or right about keeping the CC disengaged or engaged when passing. It's only a personal preference.
#74
Personally I set it with two or two bars. I find the 3 bars to be too far from the vehicle ahead hence always allows others to jump in. This results in my car slowing down more often than required and sometimes abrupt slowing down. On the otherhand, 1 bar maintains really close distance and always results in abrupt slowing down of my car making the wifey really nervous. So two bars seems to be the best of both world.
#75