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So I’ve noticed the gearing in my RT is a lot longer than my mustang was. I could cruise around town in 35mph zone in 5th without the RPM’s getting below 1500 and having to downshift. I have a general rule that if you get over 2000 shift, if you get below 1500, shift. So I’ve been riding around town around 35-40 in 4th. What gear do you all use for city traffic? Never had V8 before this car and I’m learning it’s very different mechanically than all my other cars, which were all boosted 4’s.
 

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If I’m not going to need power for anything I use 1100-1200 rpm for a cruise decision. I’ll go higher if I have to combat drive by lane changing and accelerating.
 

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Haha. Ok shoulda said this was for the M6 owners only lol. 1100-1200 doesn’t bog the motor down too bad? That was like about to stall out RPM’s in my last cars. Sluggish for sure.
 

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Going below 1500 is no problem with the torque of the 5.7L. When I had mine (M6) I would often skip shift and do 1-3-5 if I was just cruising around taking it easy, at 35 that's about 1200 at 40 almost 1400, no issues there. The automatic if you had it would be about those same rpms or less at the same cruise. Just obviously don't try to accelerate hard from such a low rpm in 5th, that would be lugging but easy cruise at low rpms won't hurt a thing.

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I'm looking for 1,500 - 2,000 rpm at cruise.

Below 1,500 rpm and unless on a level road - you're not going to have much torque if traffic slows down, then picks speed back up w/o a downshift
 

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Around my area the roads are very flat. When I first bought my RT I would cruise around town in 6th gear which was 42mph @1000rpm...of course if I need to accelerate I drop down to 3rd. In fact, my shift pattern was 1, 3, 6 during my commute to work. Most folks will say that is way too low of an RPM but skip shift (stupidest invention ever BTW) forces you to shift from 1st to 4th and your RPMs drop to around 1200.
 

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So I’ve noticed the gearing in my RT is a lot longer than my mustang was. I could cruise around town in 35mph zone in 5th without the RPM’s getting below 1500 and having to downshift. I have a general rule that if you get over 2000 shift, if you get below 1500, shift. So I’ve been riding around town around 35-40 in 4th. What gear do you all use for city traffic? Never had V8 before this car and I’m learning it’s very different mechanically than all my other cars, which were all boosted 4’s.
Years ago when I was first learning to drive a car equipped with a manual -- my prior experience was with automatic equipped cars and manual transmission equipped motorcycles so I was just having to master the clutch operation and manual transmission aspect of the car -- I asked my brother in law (from whom I had bought the car with the manual transmission) and he said what he used was: 1st gear for speeds 10 mpg and below; 2nd gear for speeds in the 20mph range; 3rd gear for 30mph speeds; 4th gear for 40mph; 5th for 60mph; and 6th for higher speeds.

Really since most often one is having to drive at a posted limit and the limits are (generally) 10mpg, 15mph, 20mph, 25mph, 30mph, 35mph, 40mph, 45mph and so on 1st gear for any speed between 1mph and 19mph, 2nd for any speed that starts with a 2, 3rd for any speed that starts with a 3, and so on.

Or another way of looking at this is under "normal" operation I prefer to keep the RPMs between around 1500 to 3000. In lower gears I might even let the RPMs dip below 1500 (but not much below; really if the engine gets operated much below 1500 it only sees this low of an RPM in 1st gear) and under acceleration I often take the engine RPMs above 3K.

To 1) avoid possibly lugging the engine; and 2) to have some margin of acceleration available; I prefer to use a gear that at the desired speed means the engine is not at the very bottom of its usable RPM band but a bit above it, so I don't have to downshift if I need to accelerate any. I'm not talking about an emergency acceleration event just the normal acceleration that is very common when operating a vehicle in normal traffic with the normal variation of speed one experiences as one strives to keep up with traffic or avoid getting too close to the vehicle ahead when other vehicles slow down a bit.
 

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1-3-6 was too big of a drop for me, sometimes I would do 1-2-4-6 if the speed limit was 45 or more and I knew I would getting to top gear if not, the 1-3-5 was easier and worked better for me.



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I generally up shift at around 2K rpm but will stay in that gear down to around 1200. I cruise 35-40mph in 5th, if I have to slow to 30mph I drop to 4th. I don't usually go to 6th until 60, but will let it drop as low as 50 if I'm on a flat road.


Coming from the small block chevy world, it took me quite a while retrain myself. The amount of low end torque these hemis make is considerably more than I was used to.
 

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On my 2015 oil pressure can be selected in the instrument cluster.
On my 2014 too, but it's a pain to use. I like having the important stuff immediately available, so I added an oil pressure gauge, fuel pressure gauge and voltage gauge together with my wide band and boost gauges.
 

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Forming an opinion on what is/is not bogging the engine would easier if we had oil pressure gauges.
these engines have 30 - 33 PSI @ idle and once you're at 1,500 rpm, typically 55-57 PSI at cruise, fully warmed up engine and oil.

So an oil pressure gauge isn't going to be of much use to determine bogging. If you hear that hum from the driveline trying to give more throttle, odds are you're below 1,200 rpm and you're better off downshifting to a lower gear.

I have a friend back in Portland the lugs the engine and I can hear the driveline NVH and the engine pinging...

If you had instant MPG readout, you'll see how low the vacuum level and fuel enrichment (low MPG #, single digits) takes places loading an engine up at low rpm vs. shifting to lower gear with less throttle %
 

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these engines have 30 - 33 PSI @ idle and once you're at 1,500 rpm, typically 55-57 PSI at cruise, fully warmed up engine and oil.

So an oil pressure gauge isn't going to be of much use to determine bogging. If you hear that hum from the driveline trying to give more throttle, odds are you're below 1,200 rpm and you're better off downshifting to a lower gear.

I have a friend back in Portland the lugs the engine and I can hear the driveline NVH and the engine pinging...

If you had instant MPG readout, you'll see how low the vacuum level and fuel enrichment (low MPG #, single digits) takes places loading an engine up at low rpm vs. shifting to lower gear with less throttle %
My observation is to a certain point operating the engine at a lower RPM at a higher load -- IOWs in a higher gear at a lower speed -- which results in the throttle being opened wider -- improves fuel economy. (The wider throttle opening reduces pumping losses and improves cylinder filling.) When I operated my GTO in this fashion, for instance I would get the transmission in 6th gear with RPMs around 1250 or so, the instantaneous MPG display would rise to the mid 30mpg range. From a 6.0l 400hp engine that was sweet.

This is one reason why automatic equipped cars have a shift map that gets the transmission in the highest gear possible. My Hellcat in D mode will up shift and be in 6th gear at surface street speeds. I believe it can get into 8th gear just a bit over 60mph.

When I leave the transmission in D and let the shift map control the shifting, the tach needle hovers just over 1K RPMs.

However, with my GTO operating in this fashion, the downside was if I had to give the engine any throttle at all the instantaneous MPG reading would fall like a stone from 30mpg+ to sometimes down to the single digit range.

I see something similar with my JCW. Instantaneous MPG can be quite high, in the 40mpg to 60mpg (or higher) range if I operate the engine at a relatively low RPM in a higher gear. But any application of throttle has instantaneous MPG drop like a stone.


And I've observed similar behavior from my Hellcat, although the instantaneous MPG numbers never get close to matching the numbers the JCW can produce.


While of course we all strive for better fuel economy there's a balance. If I had a stretch of empty road to myself I could drive in such a way either my Hellcat or JCW would deliver exceptional fuel economy, relatively speaking. But I don't have that stretch of road. I have to drive sometimes, make that oftentimes, in rather heavy traffic and the normal dynamics of this, the constant speed changes to deal with what other vehicles do around mine, requires I keep the transmission on a lower gear so the engine is not borderline lugging, and so acceleration is better when I inevitably require it.
 

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Factory skip shift wants you to cruise 25mph in 4th as long as you dont dump the gas it cruises just fine
the skip-shift algorithm was to coax better MPG numbers in the EPA City test. Nobody would shift to 4th @ 21mph unless you're going downhill
 
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