You don't want to be rolling with the engine off - the abs doesn't work nore the power steering and it is not designed to operate without the PS pump turning. Owners manual says not to turn the engine off and they also don't recommend bump starting either (in manual tranny).

For those of you that "don't get it" you put it in neutral when you WANT to coast and don't need to slow down. in the 06xB 5th gear will engine brake down to 20mph then you need to press in the clutch or the engine will kick as the injectors start to fire fuel again at around 1000 rpm.

 

Actually - our car (tC) still has power assist, and vacuum in the breaks. Bump starting has been proven to not wear out clutch/plates.

Maybe it's different for the xB....

 

You can bump start the xB by just popping the clutch out and in and it even starts easier than with the starter motor but the owners manual does not recommend it. Vacuum assist remains for a few pumps but if the abs kicks in not sure what would happen to the vacuum in the brakes. Big thing is the power steering - no way are you going to be able to whip the wheel to avoid that stupid dog running out into the road without power steering operating.

 

Agreed w/the power steering scenario. When you are rolling, along w/the limited electrical assist, you aren't at 100% manual steering, but it is much harder. I've been doing this for awhile and there are scenarios where you don't want manual steering (such as the side streets).

 

here's my 2 cent. as long as the RPM is not too low or too high for the speed you are moving at, you should save gas. I say this because at this optimum RPM, you are lightly on the gas. if the throttle is not openned very much, there will be less O2 going through, and thus the engine will inject less fuel. This situation would occur more than likely when you are cruising ( maintaining speed). Maintaining speed is achieved when the engine speed and the wheel speed are the same, which means the RPM is not too low (RPM speed<wheel speed) or not too high (RPM speed>wheel speed). when there's an imbalance in the 2 speeds, your car will try to undo the stress caused by this imbalance back to a perfect balance between the RPM and wheel speed. this in turn wastes fuel.

so to summarize, everyone's point here holds some truth and no one idea is wrong. All these ideas work cohesively and are indirectly related to each other. sometimes, i find myself at 5th gear going 20mph, but I am barely on the gas. however, I am not trying to accelerate. If I was, i'll drop it to 4th or 3rd depending how much power i need. i think the key thing is to try to stay off the gas.

 

you are right.. but... " i find myself at 5th gear going 20mph"

are u sure about the numbers???because im pretty sure when im in 5th i never go under 25.. because i can tell my car dont like it...
ok i have headers, blahblah blah = no low end power.. maybe thats the diff.. between our cars.

 

Yeah it depens upon the gearing - the tC is a little taller in 5th whereas the xB is turning a little over 1000 rpm in 5th at 20mph and it can produce enough torque at that rpm to keep moving. Going up steep hills at 25mph in 5th is a little tough but it can do that too, just don't expect to accelerate too quickly. I have the advantage of using Synlube in my engine which has superior lubricating properties at very low RPMs compared to conventional oils and Synthetics. Having gone up a hill in 5th then 4th and then 3rd I do see a little less MPG (2-3mpg less) reading in the lower gears than in the higher gears and for a really long uphill I would use a lower gear to improve cooling and reduce the strain.

 

20mph in 5th? No way.

Down shifting does not wear out your clutch anymore than up shifting if you rev match and do it carefully.

I don't think everyone here realizes that when one's engine braking, the injectors shut off. So in turn, when you are engine braking you are saving your brakes and gas. Obviously this needs not to be taken to the extreme, before I get flamed.

 

when you engine brake. you are not on the gas so your fuel consumption should be similar to idle if not the same. it saves you brakes, but i dont see how it would save gas VS. rolling on neutral and applying the brakes harder.

my 20mph on 5th was not done in a TC. I am sorry for not mentioning that, but the point of my post was the concept/idea, which should apply to any manual vehicle.

 

The point was that engine braking down to about 1000 rpm uses 0 gas since the injectors are completely shut off during engine braking whereas if in neutral it burns 0.1-0.2gph idling.

The other reason that I drive in 5th at such a low speed is because the speed limint around here (all of Newport) is 25mph so there is no need to be accelerating quickly since the speed limit can be reached and exceeded in any of the 5 gears.

 

Don't know about other cars but tC will not handle 20mph in 5th.

As Jan06xB said, the injectors are off when you are engine braking. The "gas" pedal opens up your throttle body so the engine vacuum is increased. More air in your engine, more fuel the injectors spray. When you are not on the throttle the injectors are not spraying. Only in idle are you wasting fuel as the injectors are on to prevent your engine from stopping.

 

sorry guys. i forgot to consider that the TC had drive by wire. as long as i am able to heel-to-toe downshift, i m all good to go .

 

As I recall from my one drive in a tC that the gas pedal was pretty touchy at small throttle openings and it was an automatic so there was no clutch to control my speed backing up. Man what a difference in visability looking through the windshield too compared to an xB.
As far as the lowest RPM you want to avoid rpms that produce excessive power pulsing when you can feel each cylinder firing then it is time to increase RPM by dropping a gear or two. BTW a low RPM for about 5 minutes or so seems to reduce the lubrication in the engine and the high mileage I get starts to drop off. Usually I get aboubt 60mpg at 25mph in 5th but it doesn't like that slow a speed for very long. 30-40mph is great for half an hour or more and can get me 55mpg average like on country roads.