Some people say that when you are city driving, you should keep your car in drive. Some people say that you should always have the car in overdrive.

What's your say?

 

Well I keep mine in OD when driving, and D when racing. I notice a stiffer shift when its in D (Atleast I think, might be all in my head )


I should have ran my car down the track in OD and see if it was faster or slower then when in D. If it is, im sure its not by much.

 

OD is fourth gear. In D you have three gears, and then torque converter lockup. I understand you can burn up the 3/4 clutchpacks faster with too many 3/4 upshift and downshift activity. I burned up heavy duty clutchpacks after about 11,000 miles off a fresh performance rebuild of my 700R4. Whether the guy who built the transmission was full of it or honest I cannot say - but I did drive around in OD and he said it can wear the transmission fast - but a lot of people have no problems.

I personally keep it in D, for peace of mind. Thats what it boils down to. I upshift to OD when I need to for highway.

 

.

 

When in OD the torq conv locks in 2nd, 3rd and 4th but not in first so you should not see any diff in rpm's when in the car is in first and gear select is in either D or OD. The TQ does not lock when the gear select is in D so to get the best gas mileage you should be in OD BUT as stated than can be hard on the 3/4 clutch pack. Now on a stock eng/trans you are prolly alright driving in OD all the time but once you start pumping up the HP and need the car to run higher in the rpm range you start having problems with the clutch packs and also get an unresponisive car. I am going to a fully manual TQ lock by putting in aftermarket shifter and handle with a buttom on it so it locks the TQ when the gear select is in 2 and D.

My Accel computer sometimes locks the TQ when not in OD and actually like the feel of the car being in 2nd or 3rd with the TQ locked and RPMs' above 3000, only problem is when this happens it also locks the TQ when shifting off the line during normal aroudn town driving causing the rpm's to go above and below my TQ lock setting and the car lunges and bogs back and forth. Not sure what the problem is but I ended up putting a switch so I could turn the lock off and avoid this. I want to fully bypass the computer so I decide when to lock and unlock the TQ.

 

I drive in D whenever I am cruising below 50mph to keep the rpms up and to keep it from constantly shifting.

I don't know if this is normal, but my car will hold any gear that it is in and it also shifts to 4th at WOT (if I am on OD).

 

Zepher - your 700R4 has a shift kit & and a 4th upshift kit.

I get TC lockup in D. It goes 1/2, 2/3, 3 - Lockup. Lockup drops the rpms a smidge. So in 3rd I am holding 40mph at say 2250rpm and LOCKUP drops them to 2000rpm. (rough example)

 

Only thing is, is that it doesn't feel like it has a shift kit in it. the shifts aren't firm at all.
I also run at 2K at about 40-45mph,
http://www.transamws6.com/video/formula_inside.wmv

 

If your shifts aren't firm or have been getting worse, check your fluid level. You MUST check the fluid level with the engine running and trans in park.
I keep my trans in OD because I like how my car will pull just fine in 4th gear with the TCC locked and below 30mph (I have 3.73 gears so it's about 1200rpm or somewhere about there). It feels like it's a BB in a heavy truck and I only need to squeeze the throttle for the TCC to unlock and give me ~2400rpm still in 4th. Keep in mind I also tune my eprom for these custom settings and I have an SLP shift kit which can hold any gear I keep the shifter in. Also, in 1st and 2nd the shifts are extra firm, 3rd (aka "D") it's not as firm, and in 4th (aka "OD") it's nice and stock, still firm shifts but nothing nearly as firm as leaving it in 2nd.
I want a 4L60e and a PCM with the $0D mask, then I can control the line shift pressures, shift points and all that jazz. Oh, and one thing that's a pain is not having that 4th gear kickdown valve. Right now it'll kick down into 3rd too early.

 

so what would you guys suggest for best power/speed V.S. best gas mileage

for city and highway

D or OD?

 

When i had my auto, id keep it in D until i got to a steady cruising speed or if i went to the highway. I hated when the motor bogged itself at 40mph. Best mpg is probably OD but i didn't like how the car would constantly hunt for gears and what not. Less wear and tear i would think by manually shifting D to OD when it needs to go.

 

Just leave it in OD (4th gear) for city driving, for one reason it will not shift into OD until over 40 MPH. Also you should not notice anything different when it dose shift out of OD except the RPMs will increase. Example: OD @40 MPH = 1000 RPMs vs 3rd @40mph = 1500 RPMS. That is why they call it Automatic.

 

probably a pretty noob question..but can you shift to od from d while your gassing it or is that pretty bad for it all

 

That won't hurt it. You are basically moving the selector into OD while the torque converter is doing it's things. When the vacuum gets to a point where it wants another gear (and you've let it) it will go into OD from there.