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Hello all,

I wanted to see if anyone uses the manual shift to save gas. Anyone have input on what I should be getting city if shifting below 3,000 RPM's in a 2011 RS? Is it bad for the car long term?

Also, any recommondations for gapping my sparkplugs? My plugs were all inconsistantly gapped below .25...I tried gapping them to.35 but my MPGs went way down.. then tried .30 and it is still down but not much... thinking of trying .25 to see if it helps. Does it take time to see results after gapping the sparkplugs?

Thanks!
Mike
 

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The only time I use the manual shift is when I'm feeling a little frisky and want to get down on it! Of course this does nothing to help the fuel economy so I cant address your first question. Set you plugs at 28, you should be able to tell the difference immediately.
 

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Shift at 2000-2300 whenever possible to keep the car from revving high. This engine has lots of low-end power and when it revs to 3000+, it just wastes fuel.

Manually shifting the automatic doesn't harm anything - the transmission works exactly as it would normally except the car isn't horribly picking shift points.

Plugs gapped at .030" should do just fine and may improve your response off-the-line. Don't fiddle with the iridium plugs too much or you'll break the tips.
 

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I could totally see it helping mileage over the factory shifts. When I had a auto to drive I kept getting shift denied messages. That trans is picky on when it can go into 4th gear.
 

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yeah i actually used manual mode quite a bit when i was stock. after the tune i dont find i need to. If your drive also includes a lot of hills and elevation changes its much easier to stick it in 6th and hold than to try to guess what throttle position is just enough to hold decent momentum without the computer downshifting. With the trifecta tune only when im going to be going over very steep grades ill bump it into high boost mode and stick it in 6th and putter right up. Like someone else mentioned once in manual mode at a stop you can select 3rd and still launch with decent speed. even stock with just a K&N drop in filter and resonator delete i could out pull most traffic in third. tuned is no problem at all. Also with the manual mode the first time it will select 1st gear automatically at a stop but mine learned that if i launch in third it will only drop to third.
 

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I could totally see it helping mileage over the factory shifts. When I had a auto to drive I kept getting shift denied messages. That trans is picky on when it can go into 4th gear.
It would hate me! I go 1, 2 maybe 3 and then 6. Maybe that is what is killing my MPG some. Maybe I ought to try those other gears 4 + 5 and see if MPG goes up some. I am not a big fan of shifting "too much". Maybe that is why I like a 5 spd?
 

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It would hate me! I go 1, 2 maybe 3 and then 6. Maybe that is what is killing my MPG some. Maybe I ought to try those other gears 4 + 5 and see if MPG goes up some. I am not a big fan of shifting "too much". Maybe that is why I like a 5 spd?
Yessum. Use your gears and keep it below 2000 if possible. Having lots of gears and (for my car) closely spaced gears means you can keep the revs low without giant gaps in between gears like most 5 speeds. The Eco is spaced much more widely, but members here do the same thing with those models.

My dad was amazed when I was in 6th by 35-40 mph - their Accord can't go into 5th until 45-50 or it will bog down, and the gap between 4th and 5th is huge.


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yeah i actually used manual mode quite a bit when i was stock. after the tune i dont find i need to. If your drive also includes a lot of hills and elevation changes its much easier to stick it in 6th and hold than to try to guess what throttle position is just enough to hold decent momentum without the computer downshifting. With the trifecta tune only when im going to be going over very steep grades ill bump it into high boost mode and stick it in 6th and putter right up. Like someone else mentioned once in manual mode at a stop you can select 3rd and still launch with decent speed. even stock with just a K&N drop in filter and resonator delete i could out pull most traffic in third. tuned is no problem at all. Also with the manual mode the first time it will select 1st gear automatically at a stop but mine learned that if i launch in third it will only drop to third.
Careful with starting from 3rd. You're slipping the torque converter (like a clutch in a manual) like crazy to do that and should avoid that. It creates a ton of heat and may burn the transmission fluid.


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I use the manual mode, but mostly for holding a lower gear for a corner, hills or slowing down for a stop sign. I am of the strong belief of getting up to your final speed quickly burns less fuel. Sure I burn more fuel when I am getting on it but let say I want to go 60mph, I certainly burn less in my 8-10 second blast and leveling out at 40mpg+ for a longer period than taking forever to get there shifting at 2,000RPM and constantly being under load for longer.

This is also why GM geared 1st so low, to get the 3,000LB car moving off the line with less load. Use 1st if you want to save fuel, just make sure to shift at 2500-3000RPM max. This gear is just meant to get you rolling, and the 2 seconds max you are actually at 3,000 doesn't burn that much fuel.

I usually shift at 2,500-3,000RPM in every gear, thought sometimes I take 1-4 as high as 5,000RPM. I average 36-37mpg driving this way(60% highway).
 

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Careful with starting from 3rd. You're slipping the torque converter (like a clutch in a manual) like crazy to do that and should avoid that. It creates a ton of heat and may burn the transmission fluid.
You are so correct on this & I actually think the 3rd gear at stop signs is a a software glitch with the automatic & all of them should be recalled to fix it. If I am using manual mode in town I have to make sure what ever I do I don't take off in 2nd gear, or roll a yield/stop in 3rd. If I do these things the automatic sometimes forgets that it always automatically downshifts to the appropriate gear & will be sitting in 3rd gear at the next stop sign I come too.
I understand this is normal behavior for 2nd(for winter traction, see owners manual), but there is no reason it should ever be in 3rd gear and not moving. You can sure feel this is not normal or good, adds a considerable shudder to the car.
 

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I find the car coasts better while in manual mode than in drive. I usually put it in m6 anytime I will be maintaining more than 43 mph for more than a few miles. I usually take off in drive though as I have a hard time shifting the lower gears as fast as drive does. When in drive it usually shifts arounf 2200-2500 for me.

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I use the manual mode, but mostly for holding a lower gear for a corner, hills or slowing down for a stop sign. I am of the strong belief of getting up to your final speed quickly burns less fuel. Sure I burn more fuel when I am getting on it but let say I want to go 60mph, I certainly burn less in my 8-10 second blast and leveling out at 40mpg+ for a longer period than taking forever to get there shifting at 2,000RPM and constantly being under load for longer.

This is also why GM geared 1st so low, to get the 3,000LB car moving off the line with less load. Use 1st if you want to save fuel, just make sure to shift at 2500-3000RPM max. This gear is just meant to get you rolling, and the 2 seconds max you are actually at 3,000 doesn't burn that much fuel.

I usually shift at 2,500-3,000RPM in every gear, thought sometimes I take 1-4 as high as 5,000RPM. I average 36-37mpg driving this way(60% highway).
My fuel economy has gone up by about 8 MPG once I started targeting the end of shift starting point for the new gear no higher than 1400 RPM. This still lets you get off the line reasonably quickly as the first shift is at 2300 RPM and the second shift is at 2000 RPM. Yes, I'm also doing other things like slowing down from 65 to 60 (which is safe on my morning commute) and even 55 in the afternoons (once again, a safe speed), but in heavy stop and go traffic there is a noticeable 6+ MPG increase just from changing my shift timing.
 

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Careful with starting from 3rd. You're slipping the torque converter (like a clutch in a manual) like crazy to do that and should avoid that. It creates a ton of heat and may burn the transmission fluid.
You are so correct on this & I actually think the 3rd gear at stop signs is a a software glitch with the automatic & all of them should be recalled to fix it. If I am using manual mode in town I have to make sure what ever I do I don't take off in 2nd gear, or roll a yield/stop in 3rd. If I do these things the automatic sometimes forgets that it always automatically downshifts to the appropriate gear & will be sitting in 3rd gear at the next stop sign I come too.
I understand this is normal behavior for 2nd(for winter traction, see owners manual), but there is no reason it should ever be in 3rd gear and not moving. You can sure feel this is not normal or good, adds a considerable shudder to the car.
I agree with both these points, actually, and I complained about being able to start from a dead stop in 3rd about a year ago.
 

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My fuel economy has gone up by about 8 MPG once I started targeting the end of shift starting point for the new gear no higher than 1400 RPM. This still lets you get off the line reasonably quickly as the first shift is at 2300 RPM and the second shift is at 2000 RPM. Yes, I'm also doing other things like slowing down from 65 to 60 (which is safe on my morning commute) and even 55 in the afternoons (once again, a safe speed), but in heavy stop and go traffic there is a noticeable 6+ MPG increase just from changing my shift timing.
My whole point was all of you are missing utilizing the gearing of the car(torque multiplication) by not taking at least 1st to a higher RPM. Tested this today, from a full stop in M1 still using a light foot(less than 1/4 pedal)I was on the gas a total of 3-4seconds but was already up to 12mph or so. This also placed 2nd nicely in the power band so one can get up to 25-30mph with a total of 6 seconds with of gas. Then I just cruze along in 4th or 5th depending on terrain(27mph is the lowest you can use 5th with the auto). I would have to check what RPM I am hitting in 1st, but think its about 2800-3500RPM over those few seconds.

This Generic MPG graph below from Fueleconomy.gov show just how important getting 3,000lbs moving with the least amount of work is, and just how important it is to utilize 1st to a higher RPM to get you moving.

 

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Buy the trifecta tune they fix the shifting to optimize it. If you want to shift the car yourself, buy a manual transmission car and be done with it.

2nd what spacedout said. The Automatic transmission gears (4.58 and 2.96) are specifically there to motivate this porkster. Skipping either is counterproductive.
 

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Buy the trifecta tune they fix the shifting to optimize it. If you want to shift the car yourself, buy a manual transmission car and be done with it.
I'm doing it wrong.
 
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My whole point was all of you are missing utilizing the gearing of the car(torque multiplication) by not taking at least 1st to a higher RPM. Tested this today, from a full stop in M1 still using a light foot(less than 1/4 pedal)I was on the gas a total of 3-4seconds but was already up to 12mph or so. This also placed 2nd nicely in the power band so one can get up to 25-30mph with a total of 6 seconds with of gas. Then I just cruze along in 4th or 5th depending on terrain(27mph is the lowest you can use 5th with the auto). I would have to check what RPM I am hitting in 1st, but think its about 2800-3500RPM over those few seconds.

This Generic MPG graph below from Fueleconomy.gov show just how important getting 3,000lbs moving with the least amount of work is, and just how important it is to utilize 1st to a higher RPM to get you moving.

My own experience mimics that of Mikes. Keeping the RPMs at or below 2000 with gear changes and accelerating at a reasonable pace can put my car above 34 mpg in city or stop and go traffic. By doing this, you're keeping out of boost as much as possible. Before, I would run gears out to 3000-ish (then dropping into 5th-6th immediately) because it was more fun and never got more than 28-29 mpg in the same driving.

However, my Cruzes acceleration lags quite a bit even on 93 with the AC on and I have to rev the gears out a bit more to 2300-2500 to get the same acceleration.

XRs "ultra Eco tune" post explains why this happens with the Cruze a little bit. The more boost you apply to a turbo engine, the more fuel is thrown away trying to cool down the cylinders and keep knock from happening. It creates more power, sure, but you're wasting more fuel than an NA Engine driven under the same conditions.


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It is interesting reading about the different driving styles with auto. I mostly just leave my car in drive and even going down a slope at 50kph (30mph) the transmission senses when you don't want to go any faster and will hold a lower gear all by itself. I read something about this feature in my owners manual and it works, at least with a diesel and 6T45 anyway. High compression = good engine braking. The new 1.6 turbo senses when you are pushing along and will hold a gear when you slow for a corner to give a better exit as well. Holden re-tuned the transmission for sportier driving when required.
 
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