View Full Version : Downshifting w/automatic transmission in the manual mode
JeRKy 8 Owner 11-13-2003, 12:31 AM I dont know if the Rx8 is supposed to be doing this. I drove in afew other tectronic cars this weekend and none of them let you shift down to the 1st gear once you were in 2nd until you got below 8mph.
For some reasonin my Rx8 I can shift it down to 1st as long as I am at 27mph or under. When I do this, the whole car shifts and it feelslike the engine is crunchingor something. Going from 3rd to 2nd doesnt have that much of a pound like this does.
I thought itwas normal so now that Ive started always driving with the paddles in manual mode I started to just shift to 1 instead of using the brakes. Ithink Ive messed up the transmission a little b/c now when the car goes from 2nd to 3rd or 3rd to 2nd or 1st to 2nd it feels really rough. I havea feeling its b/c I was downshifting to 1st from 2nd too high and using that as a meansof slowing down the car instead of just using brakes.
Am I actingparanoid or have I possibly messedsomething up by driving the car like this?
JaChTsai 11-13-2003, 12:33 AM I'm wondering about that too. I downshifted with paddle shifters when I was at like 20 mpg, and it threw me back a little.
mazdabob 11-13-2003, 12:51 AM The transmission will not downshift if it would cause the engine to overrev. The owners manual indicates at what speeds you can downshift in each gear. If you try to downshift too soon, the gear number indicator will flash - meaning you can't do that. (I've accidentally done it, so I can verify this) As far as the jerky downshift, if you are on the gas, it will shift smoothly. But, if you are slowing, it will be jerky. I've had an Audi and a Passat with tiptronic automatics, and they electronically blip the throttle when downshifting. Ours does not seem to do this. One thing you can do is keep on the gas slightly as you downshift, and then back off the gas pedal.
Gord96BRG 11-13-2003, 09:32 AM Originally posted by JeRKy 8 Owner
I thought itwas normal so now that Ive started always driving with the paddles in manual mode I started to just shift to 1 instead of using the brakes.
Brakes are a whole lot cheaper to service and replace than transmissions and engines. Use brakes for deceleration - downshifting is for being in the right gear for acceleration after the corner/stop. This applies to manual transmissions and autos as well!
Regards,
Gordon
mazdabob 11-13-2003, 12:19 PM Actually, if you use your brakes a lot when driving in the mountains and traffic, there's a good chance you will warp your rotors and wear your pads sooner. Rotors and pads are not covered by your warranty. Transmissions ARE covered by the warranty. Automatic transmissions are very reliable, and if there's a problem, it's unlikely that they could prove that you abused it.
blizz81 11-13-2003, 12:43 PM Originally posted by mazdabob
Actually, if you use your brakes a lot when driving in the mountains and traffic, there's a good chance you will warp your rotors and wear your pads sooner. Rotors and pads are not covered by your warranty. Transmissions ARE covered by the warranty. Automatic transmissions are very reliable, and if there's a problem, it's unlikely that they could prove that you abused it.
Then you have to ask if you're willing to go through the trouble of having your car serviced for an auto tranny rehaul, as opposed to doing a more simple brake job yourself. I mean, yeah...in the case of mountain driving, I would probably do more engine braking. But it's not like I or the people in question work at the gift shop on the top of Pikes Peak and drive to work every day in a sports car. In general on the streets of everyday life I would let the brakes do the braking, esp with an automatic transmission which, if it fails out of warranty or for some reason they argue covering it, you're looking at a whole lot more headache (even when compared to the same situation and your normal manual transmission).
mikeb 11-13-2003, 12:50 PM When you slow down in 2nd the car will automatically put you in first
Astor 11-13-2003, 12:57 PM For manual transmission (not sure if my manual is different than automatics) it mentions to never put your car in 1st unless you are under 20 mph.
JeRKy 8 Owner 11-13-2003, 02:55 PM Thanks for the info guys. The otherthing I like about this is I barely get any brake dust on my front two rims since I barely use the brakes to slow down.
Originally posted by mazdabob
Actually, if you use your brakes a lot when driving in the mountains and traffic, there's a good chance you will warp your rotors and wear your pads sooner.
The rotors on the 8 are huge. When I first saw them I said to myself "there is no way my wife can warp these things.":D
s1mike22 11-13-2003, 03:55 PM i wouldn't recommend downshifting to 1st gear at speeds such as 27 mph.....
Mitch Strickler 11-13-2003, 05:14 PM My idea of satisfying sports driving is to respect the machinery, using it smoothly to do what it is designed for. That gets better results and a car that runs well longer.
The RX8 brakes, particularly with the 18" package, are made for heavy use. Read the Yamaguchi book: they beat the best in class for 10 consecutive stops from 100 km/h with nil fade. The A/T is not designed to be jerked around to substitute for brakes, and it happens to be a makeover from an old tranny not intended to handle RX8 performance.
I agree with Gordon on how to use the transmission. The only time I can imagine where engine braking would be called for to ease pressure on the brakes would be a very long, steep downhill run. Near the top, 2d, or 1st, could be engaged smoothly (brake down to a reasonable speed for the chosen gear and use the throttle to ease the possibility of jerking). Then leaving it in that gear to keep from picking up too much speed on the descent. A rare situation, IMO.
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