Sport Mode

[88nitro305]

Ok well my 2007 Legacy 2.5i has sports mode... now a guy i work with has an Outback with the same and says he doesn't break instead will use that kinda like a truck with a Jake-Break i guess... he said to do that it won't harm anything now i haven't done it cus i wanted to check with all of you... does it harm your motor or transmission or anything for that matter?

[DLC]

If you're talking about engine braking, then that's a benefit/feature/bug with the Sport mode on the new models that I was unaware of.

It sounds like the transmission is using the gear that would be best for acceleration, so it's not staying in top gear, or a high gear, when slowing down, but it's acutally downshifting. This is akin to a what a driver in a car with a manual transmission can do by downshifting into each lower gear as they approach a light/sign/corner/hooker, letting the engine compression slow down the car.

It won't harm the car, but it uses a tiny bit more fuel and adds a minute bit more wear to the engine.

I do this all of the time in my car.

[Sarra]

Sport mode keeps the RPMS up by shifting, no? IMO, it's what automatic transmissions should do anyway.

[99SUS SFD]

Yeah I think sport mode just keeps your RPM's up for a better throttle response when you hit the throttle. It's going to consume more gas because it's staying in a higher gear at higher RPM's to give you "instant" throttle response.

[Huffer]

You mean lower gear at higher rpms. ie. 3rd gear at 5000rpm instead of shifting to 4th gear when you hit 3500rpm.

[99SUS SFD]

Yeah...that. :grin:

[jey]

It won't harm the car, but it uses a tiny bit more fuel

That may not be true. When you are engine braking above about 2000 rpm or so with 0 throttle, the injectors on the car are shut completely off - you are consuming 0 gas. When you are idling or close to it at 1500 rpm, the injectors come on and you are consuming some gas. You can even feel this especially on older cars as you engine brake - you can even feel the point around 2000 rpm when the injectors come back on.

[DLC]

jey: I think I've heard this before, and I hope it's the case. Good info.

[Sarra]

There's been debate on NASIOC about this. The debate goes like this:

Side one says that all cars shut off the injectors when at 0 throttle

Side two says that ODBII cars reduce Duty Cycle on injectors to below idle levels, but still inject SOME fuel to keep the cats warm enough to be effecient.

Having no direct evidence either way, I don't know what to say. Either way, decelerating uses less gas than idle, so you're going to save gas by downshifting when decelerating.