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Discussion Starter #1
I have to share something I’ve been trying out lately. For the past couple of years I’ve been driving a 4 cylinder, 5 speed manual Camry and I actually use the gated shifter in my V6 Rav4 kind of like a rev-limiter. In my neighborhood where the speed limit is 30 mph, if I stick into 3rd gear at 2000 rpm I’m going 30 mph. In 4th gear at 45 or 50 mph, it’s at 2000 rpm! And finally at 70 or 75 mph it’s at 2000 rpm.

I think driving around town in 5th gear (D) @1300/1500 rpm is ridiculous and causing erratic RPM’s by downshifting, resulting in unnecessary gear hunting and possibly hurting the overall gas mileage. I would think that a constant 2000 rpm would be better for gas mileage as well as wear and tear on the powertrain, instead of 1500 to 3500 back down to 2200 rpm and so on.

The owner manual specifically states “NOT” to lug the engine during the break in period; if I did this in my Camry, it would be seriously lugging the engine. Anyway, before anyone says it’s bad for the tranny, look in the manual under engine braking. The numbers are amazing to see when you can down shift and at what speed!

My gas mileage results are showing a positive outcome as well. My first tank is considered insufficient data, due to not knowing how full it was from the dealer. My second tank was driven by myself and girlfriend without using the gated shifter, resulting in 25 mpg 80/20 hwy. My 3rd and 4th tanks have gone up to 26.5 mpg (myself driving) with the climate control set at 80 degrees in 100+ degree heat, same 80/20 hwy. Maybe others could try it out and report back?

P.S. I’m not playing Ricky racer, just driving by the tachometer as a test :lol:
 

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I have found with my V6 that it does seem to "lug" often when going under 40 or so and I tend to put it in 4th which keeps it from shifting into the highest overdrive gear, it runs very good there. When I get up to freeway speed I put in back in D.

By the way, you are using the gated shifter everytime you take it out of park in put it in drive.
 

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I agree with you. After 25 years of driving manual transmissions, I have now had my RAV 4 V6 for 3 weeks. I find myself constantly using the brake when I get too close to the car in front of me as the trafic slows down and speeds up. With the manual transmission on a 1999 Camry V6, I would leave it in 4th gear around 35-40 MPH, 3rd around 25-30 and shift down to 2nd around 20 MPH. This way, I could use minor engine braking if the car in front of me slowed down slightly.
A long time ago, I had a 1973 Mercury Capri 5 speed V6. I remember being told never to let the RPMs go below 1500. At some slower speeds, the RAV4 RPMs are around 1200 and the transmission will keep changing gears with the slightest touch of the accelerator. I've been playing around with the 3rd gear setting around 2K RPM. I will only do this in heavy traffic. I too wonder if this causes excess wear on the transmission. I can't see any other need for the 4,3, and 2 settings. I'm in a area with no hills.
 

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Discussion Starter #4
Hey Barny, yes I guess you could say I'm using mine like a 3 speed. I start out in 3rd shifting up to 4th, then to "D". My shift points are at @ 2200 rpm's. When downshifting, I do the same as Whizzobutter, when traveling down the two lane highway to work and someone is going slow, I'll downshift to 4th using the engine to brake for me. However I have noticed if I get off the freeway and don't come to a complete stop, downshifting to 3rd takes a moment to kick in. So if I know it's a rolling stop it goes into 4th. Knowing I'll be coming to a complete stop, it goes into 3rd. I find it works very well. As I mentioned before I'm still experimenting with it all.

Whizzobutter, seems we come from the same school. I see from another thread you're a cyclist as well? Most cyclist have a more of an understanding as to the damage lugging can do. When I pull to high of a gear on my bike, the least point of resistance are my knees which adds stress to the joint. I see my knees being used just like piston connecting rods, it's got to add stress to them :shock: Who knows I could be way off :roll:
 

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I have no idea if what you are doing is hurting your transmission or resulting in better gas mileage. Just thought I would point out that you would expect to see better gas mileage anyway as your engine breaks in, so I don't see how you can seperate that from your shifting style. I myself just started to see significantly better mileage on about my fourth tank on about the order you are seeing. A better test would be to alternate shifting styles between tanks and compare. Of course, this would also assume that you use the car identically between the two tanks as well.
 

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From the operators manual...
-----------------------------------------------------
Put the selector lever into the “D”
when engine braking is not required.
Driving with the select lever in “3”
(4- speed) or “4” (5- speed) will reduce
the fuel economy. (For details, see
“Automatic transmission” on page 141
or 145 in Section 1- 7.)

Avoid engine lugging or over- revving.
Use a gear position suitable for
the road on which you are travelling.
-------------------------------------------------------
They seem to have left out the 5 speed xmission here but this is what they say about max speeds in the various gear settings...

Be careful not to over- rev the engine.
Watch the tachometer to keep
engine rpm from going into the red
zone. The approximate maximum allowable
speed for each position is
given below for your reference:

“3” . . . . . . . . .175 km/h (109 mph)
“2” . . . . . . . . . 113 km/h (70 mph)
“L” . . . . . . . . . . 63 km/h (39 mph)

------------------------------------------------------
Wow 70 in SECOND! I don't think we have to worry about driving in 4th (or 3rd w/4 speed)
 

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flyingn said:
you can't lug an automatic transmissioned engine.
Add to that statement....that's working properly. :wink:

I had to shake my head and bite my tongue when lugging a 2006 Rav4 was mentioned, it's not available with a manual transmission which is the only way lugging can happen, being in the wrong gear for the speed. As Flyingn stated, best fuel economy will be attained with the lowest rpm, that would mean leave it in "D" and let the transmission determine what gear it should be in for the conditions, unless you want to use engine braking which is covered on pages 146 and 147 for the 5-speed.
 

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It also says on page 146 to "Always use the "D" position for better fuel economy and quieter driving."

I'd venture to say that the lugging reference pertains to previous generations of the Rav4 with manual transmissions since it's impossible to lug the engine with an auto trans that's working properly. If it won't kick down as needed, then you need to visit your service dept.
 

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Discussion Starter #12
Okay folks, I think the whole gas mileage thing is getting blown out of proportion here; the gas mileage part of the topic was a POSSIBLE resultant of constant rpm instead of an erratic one. Let’s go back to the meat of the topic:

I said “I think driving around town in 5th gear (D) @1300/1500 rpm is ridiculous and causing erratic RPM’s by downshifting, resulting in unnecessary gear hunting and possibly hurting the overall gas mileage. I would think that a constant 2000 rpm would be better for gas mileage as well as wear and tear on the powertrain, instead of 1500 to 3500 back down to 2200 rpm and so on.”

So if I’m cruising with the rpm’s at 1300 in whatever gear at whatever speed and hit the throttle, during the downshift it goes to 3200 rpm!, that’s good for the powertrain and gas mileage? My rhetorical question was, wouldn’t it be more efficient to keep it at a constant rpm?

Another question, how does the fuel injection work? Since everything is controlled by the ECU, what regulates the fuel disbursement into the cylinder head? Engine rpm or throttle depression?

As for the bad word “lugging”, if I’m pulling around 3700 lbs. at 1200 rpm’s at a low speed around town, wouldn’t that be considered lugging 3700 lbs around? If I’m driving at 2000 rpm’s around town, wouldn’t that be more efficient? I don’t know maybe I’ve spent too much time on bicycles knowing what the cause and effect of riding around in a gear that’s too high, something is getting stressed somewhere :roll:
 

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It is working just fine, my 99 V6 Camry did the same thing until it was broken in. I do not like to lug that new engine, and also, it runs so much better in 4th, smooth throttle response, I do not care about mileage now, I just want another Toyota with 180,000 miles with 0 problems and 0 oil usage. My Camry never used a single drop of oil.
 

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Mine gear hunts a little more than I like it to also. The gas pedal is touchy so I start off real with only the slightest pressure, otherwise it wants to go like a race car, the tranny upshifts almost right away. Then I press it a little harder to slowly speed up and it is down shifting. I don't know if it is me, but I have been trying to put it in "4" and "3" to see if that changes it any. It seems to help, but I am not positive. I would give up a little MPGs to get it to not shift as much.
 

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I think the main reason the V6 gets the same highway mileage as the I4 is due to the RPM's (at highway speeds) being about a third less than the I4. Assuming the cylinders and pistons are the same size, then wouldn't the V6 at 1800 RPM get the about same gas mileage as the I4 at 2700 RPMs. I can see how the V6 running at highway speeds at low RPMs is great for fuel economy, but 1200 at some points cruising below 40 MPH seems to me like it would be hard on the engine or transmission, considering it weighs about 3700 pounds plus passengers and normal "idle" speed is about 700 RPMs.
I'm just a lowly accountant. I don't know much about engines and transmissions. This forum is great for finding these things out.
 

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I don't see the engine turning at low RPMs as being hard on the engine. It is powerful enough that it does not need to work that hard to move the vehicle. It would be hard on the engine if it was turning at 4000-5000 RPM to move the vehicle. Keep in mind the RAV is 3" shorter in length, 1" shorter in height, the same width as the HIghlander, but weighs 800LBS less, with a slightly bigger engine. It is light with a powerful engine. The way I figure is any engine only has a finite number of revolutions on the camshaft and crankshaft, a finite number of times that piston will fire, a finite lifetime on the rings and bearings. So if low RPMs conserve that serviceable life that is good. In the past people would say you could not get 100,000 miles out of a 4 cylinder engine, only a V8. Some of that is still true. Look at old Landcruisers that have V8s in them. Some of them are at 300,000 miles and still going strong. I think it is the rare exception to get over 200,000 with a 4 cylinder.
 

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Have you noticed that if you drive away while the engine is cold that it will not shift up to the highest gear until it warms up, why would they program it like that, why would they want a cold engine to rev high until it warms up.
 

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That's normal for automatic trannys with OD, it won't shift into OD until the coolant temp reaches a threshold temp. The owner's manual states such on page 146.
 

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flyingn said:
you can't lug an automatic transmissioned engine. And keeping the lowest rpm = best gas mileage
You're off base here. On the way to work, my RAV was doing about 1200 RPM @ 40 MPH up an incline (I'm assuming it was in OD). The throttle pressure was light, but it was losing speed, as there's not much torque at that RPM. The engine was lugging, but it didn't downshift.

My parents used to have a '78 chevy malibu. It had the 6 and the 3spd auto, that thing used to lug going up hills like you would not believe. It would take just about WOT before it would downshift...

It's very possible to lug an automatic transmissioned engine...

DJ
 
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