Transmissions

[TRDSmokedU]

With Chrysler, GM and now Ford announcing an 8 speed transmissions to their trucks and SUVs I could only help but realize how far behind Toyota is with the 4Runner is still sporting a 5 speed. Nissan's new Patrol or QX56 has a seven speed transmission and some the Chryslers are getting 9 speeds. Do you think Toyota will at least offer a 6 speed in the future? I know the Toyota’s Lexus division was the first to pioneer an 8 Speed transmission I only wonder if they will offer it in their truck line.

 

[SigSense]

Some newer models of the Highlander have a 6-speed tranny, so maybe future 4Runners?

 

[Quentin]

With Chrysler, GM and now Ford announcing an 8 speed transmissions to their trucks and SUVs I could only help but realize how far behind Toyota is with the 4Runner is still sporting a 5 speed. Nissan's new Patrol or QX56 has a seven speed transmission and some the Chryslers are getting 9 speeds. Do you think Toyota will at least offer a 6 speed in the future? I know the Toyota’s Lexus division was the first to pioneer an 8 Speed transmission I only wonder if they will offer it in their truck line.

More gears doesn't magically make a vehicle better. A lot of the 6 speed automatics out there, especially when attached to an engine that is tasked to pull round a large vehicle, tend to always be hunting for gears and have terrible drivability in the name of EPA ratings that don't necessarily translate to the real world. (See Consumer reports real world fuel economy between the 4AT, 4cyl Rav4 versus the 4cyl, 6AT Equinox. The much higher EPA rated Equinox returns worse fuel economy with 2 extra gears!)

A 6AT would make loads of sense in a V8 4Runner because of the extra torque low in the rev band, meaning they could really overdrive 6th gear and still be making enough power to keep the thing moving without constantly downshifting. It makes the fuel economy penalty a little smaller on the V8 (as shown by the GX460 fuel economy in a heavier, more powerful vehicle.) I don't think the 1GR V6 makes enough torque at the low RPMs to add another OD gear (which is the only reason you'd want another gear, right?). Especially being in the mountains of WV, mine would be in 4th and 5th gear all the time like it is now. I expect that the next V6 4Runner will get a 6AT, but it will be more for marketing purposes than making a substantial difference in fuel economy.

Some newer models of the Highlander have a 6-speed tranny, so maybe future 4Runners?

Not relevant. The 6AT, 4cyl Highlander is a transverse mounted drivetrain using a transmission very similar to the RX350, Sienna, Camry, Avalon, and Venza. The 5AT, V6 Highlander is an older style FWD transmission. I expect that the next gen Highlander will get a 6AT, though.

Finally, there are definite trade-offs with adding extra gears. You start adding more planetary gear sets (something else to fail), more clutch packs (something else to fail), more complex valve body, more solenoids, more bearings (yup, those can all fail). Then, consider that there is more weight spinning in the transmission. That is inertia that has to be overcome and that reduces the efficiency of the transmission. With all the extra bearings and such, there is more friction internally in the transmission. Yup, that is more resistance further reducing efficiency.

I am all about 6 gears in a sports car because you get a tight ratio gear box for fun driving while being able to have a somewhat reasonable engine speed when driving at 70mph. You don't get the same "fun benefit" from extra gears when you are driving a 4600lb SUV.

 

[aspade]

Toyota's 6 speed used with the 4.6 V8 in the GX and Tundra has the same 1-5 as the old 5 speed box with a 2nd, taller OD on top.

At face value another OD wouldn't do much good because like Quentin said, the V6 doesn't have the power to use it anywhere but flat cruise. No gain in drivability, maybe even a negative considering the constant downshifts, gain 0.5 mpg or so, not worth the cost and complexity.

So don't use it as an OD. Go the other direction and you can swap in 4.56 axles and keep the final drive exactly where it is now. That'd be worth something.

 

[philsey]

@quentin ...

Nicely stated, and informative. I drive around town in "4" because the hunting between 4th and 5th ~ 35-40 mph annoys me.

 

[JB.]

More gears doesn't magically make a vehicle better. A lot of the 6 speed automatics out there, especially when attached to an engine that is tasked to pull round a large vehicle, tend to always be hunting for gears and have terrible drivability in the name of EPA ratings......

Good post.

I don't think I would have any use for a 6th gear even with the 2uz-fe.

 

[BONASABOB]

transmission

Thanks to guys as smart as Quentin, he nailed it...this is one case where more is not better. Have only had my Trail 2 mos and as it is my fall hunting truck and not my dd,I have driven very little, all short trip suburban but the tranny gets into o d at 35-40 mph, doesn't hunt and gets 19.5 mpg. What's not to like???

 

[TRDSmokedU]

Thank you for all the information. I read that an 8 speed transmission only gets around 2 - 4% greater fuel savings which is merely at most 2 MPG. I really didn't understand why Toyota would use an 8 speed for an ISF which puts out a ton of power and not use it for the LX. Thank you for the clarification.

I guess with the new fuel standards coming Ford, Dodge, and GM are scrambling for any fuel savings they can find. It will be interesting to see if the 8 speeds are going into any of their heavy duty trucks. From what I hear, the Grand Cherokee was supposed to have a 8 speed for the Hemi but they announced it will receive a 6 speed next year.

 

[JB.]

I read that an 8 speed transmission only gets around 2 - 4% greater fuel savings which is merely at most 2 MPG.

2 mpg might be worth it.

2-4% is more like 1/2 mpg.

 

[bigbwb]

I guess my logic may be off, but I don't agree with the notion that adding a properly engineered (geared) tranny with more gears is not beneficial for the current 4runner? I am by no means educated in engineering or have much experience in automotive technology but look at the evolution of the last gen, it gained a 5sp auto versus the 4 spd with no negative effects. Also look at all the smaller econo cars with 6sp trannies that have limited torque output. How is the 4runner any different? Yes, adding an 8sp tranny will not make a night/day difference in real world MPG, but gaining a MPG or so is huge with the new CAFE regulations coming soon. I also feel the new transmissions with 6 gears or more must be properly designed to use the powerband of the motor precisely. I imagine this is how the small 4cyl cars with 6 speeds manage excellent MPG while delivering good acceleration and smooth shifting.

There are numerous Crossover and standard SUV's with 6sp(or more) trannies that are able to tow and cruise on the highway just fine. As for them being less reliable etc, dont really believe that either. Lexus has had their 8spd in the LS for quite sometime without issues I know of. Yes, there are more gears, parts, etc, but nowadays, the technology has existed for years and being perfected with each following generation.

All in all, I feel extra gears do help and truly are beneficial for the everyday car or truck if integrated properly of course

 

[Foques]

Chryslers and GM's slushboxes are falling apart like whoa right now.. with their 6 and 7 speed transmissions.. I wouldn't touch anything past 5 speed from them.

Many cars are using the 6th gear as an OD, not anything else.

I'm sure cars will develop into 6+ gear transmissions being a norm at some point, but for now, i'd stay away from it.

 

[TRDSmokedU]

I guess my logic may be off, but I don't agree with the notion that adding a properly engineered (geared) tranny with more gears is not beneficial for the current 4runner? I am by no means educated in engineering or have much experience in automotive technology but look at the evolution of the last gen, it gained a 5sp auto versus the 4 spd with no negative effects. Also look at all the smaller econo cars with 6sp trannies that have limited torque output. How is the 4runner any different? Yes, adding an 8sp tranny will not make a night/day difference in real world MPG, but gaining a MPG or so is huge with the new CAFE regulations coming soon. I also feel the new transmissions with 6 gears or more must be properly designed to use the powerband of the motor precisely. I imagine this is how the small 4cyl cars with 6 speeds manage excellent MPG while delivering good acceleration and smooth shifting.

There are numerous Crossover and standard SUV's with 6sp(or more) trannies that are able to tow and cruise on the highway just fine. As for them being less reliable etc, dont really believe that either. Lexus has had their 8spd in the LS for quite sometime without issues I know of. Yes, there are more gears, parts, etc, but nowadays, the technology has existed for years and being perfected with each following generation.

All in all, I feel extra gears do help and truly are beneficial for the everyday car or truck if integrated properly of course

I agree. Toyota was first to come out with an 8 speed. Now it seems they are falling behind. Infiniti's QX uses a 7 speed and from what I hear it tows really well.

 

[Quentin]

I guess my logic may be off, but I don't agree with the notion that adding a properly engineered (geared) tranny with more gears is not beneficial for the current 4runner? I am by no means educated in engineering or have much experience in automotive technology but look at the evolution of the last gen, it gained a 5sp auto versus the 4 spd with no negative effects. Also look at all the smaller econo cars with 6sp trannies that have limited torque output. How is the 4runner any different? Yes, adding an 8sp tranny will not make a night/day difference in real world MPG, but gaining a MPG or so is huge with the new CAFE regulations coming soon. I also feel the new transmissions with 6 gears or more must be properly designed to use the powerband of the motor precisely. I imagine this is how the small 4cyl cars with 6 speeds manage excellent MPG while delivering good acceleration and smooth shifting.

There are numerous Crossover and standard SUV's with 6sp(or more) trannies that are able to tow and cruise on the highway just fine. As for them being less reliable etc, dont really believe that either. Lexus has had their 8spd in the LS for quite sometime without issues I know of. Yes, there are more gears, parts, etc, but nowadays, the technology has existed for years and being perfected with each following generation.

All in all, I feel extra gears do help and truly are beneficial for the everyday car or truck if integrated properly of course

As mentioned above, the 4Runner would end up with the 6AT from the GX which is exactly the same ratios from 1 ~ 5 and another OD gear on top. Do you find yourself cruising down the highway thinking that you wish the engine were running at a lower RPM? That is the only thing you'd gain by adding the transmission from the GX. So, assuming you didn't change the final drive gearing, you'd be rolling around at 1500rpm or similar at 70mph. Here is the real difference. The UR in the GX460 makes over 240 ft-lb of torque at 1500rpm. The GR in the 4Runner makes around 150 ft-lb (according the the torque curves on the TIS). The GX will actually be able to pull a small incline and stay in 6th gear. The 4Runner would immediately be gearing down to pull any incline at that gear. I've put about 17k miles on my 4Runner and the gearing is already pretty tall. If you were a complete flatlander, you'd probably see a decent fuel economy benefit. I get 24mpg in my 4Runner driving through flatlands in Ohio. Going from 24mpg to 25 or 26mpg saves me practically no money at the gas pumps, though.

The problem then comes to cost. They probably determined that adding the 6AT would add X cost and would only increase sales by Y. Considering the marginal real world efficiency increase, they determined that there wasn't a cost benefit to adding the 6AT. Considering that the yen is so strong against the dollar, that is even more reason to stick with the tried and true 5AT. If they didn't just grab the GX transmission, there would be add'l engineering work in making the ratios properly suit the 1GR. That is extra cost.

As far as reliability, comparing a 6AT and a 5AT of identical designs, the 6AT has more parts and thus has more things that can go wrong. I'm not saying that Toyota's 6AT is unreliable because of it having 6 gears instead of 5. All my research indicates that the 6AT is a very robust transmission. Later in life, though, there are more clutchpacks, brake/clutch pistons, bearings, solenoids, and valves that can go bad. There are just more things that can go wrong from a FMEA perspective.

Now, if the 1GR were direct injection where it made a lot more torque at very low RPM, I could see a real fuel economy benefit coming from another OD gear. As the 6AT is geared now and how the 1GR currently puts out torque makes the 6AT less of a no-brainer when you consider the add'l cost that comes along with it.

 

[westwind77]

Why stop at 6! Why not just drop a full MAC truck tranny of 10+ in it, with the 2 reverse gears, we all want to be able to shift up/down in reverse right?

I am just fine with the 5 gears that you very much. You want 6, go buy a little sports car I don't know, maybe some people just love playing with their sticks too much

 

[Canadian144]

My mom used to have an 07 G35x sedan, with a 5 speed auto. That was a fantastic tranny... power was always RIGHT there. We upgraded her to an 09 G37x coupe, which has a 7 speed auto. I HATE the 7 speed! Anytime you want to step on it it pauses, drops a gear, and then sometimes drops another one! In a 330hp car, there should be instant power, no delay.

I think a 5 speed is fine in a truck/SUV. 6 speed would be the highest I would go - auto or manual, in any vehicle.

 

[smkied]

Why stop at 6! Why not just drop a full MAC truck tranny of 10+ in it, with the 2 reverse gears, we all want to be able to shift up/down in reverse right?

I am just fine with the 5 gears that you very much. You want 6, go buy a little sports car I don't know, maybe some people just love playing with their sticks too much

Count me in on the MAC truck tranny please, I want to be a REAL man :cowboy:

 

[bigbwb]

As mentioned above, the 4Runner would end up with the 6AT from the GX which is exactly the same ratios from 1 ~ 5 and another OD gear on top. Do you find yourself cruising down the highway thinking that you wish the engine were running at a lower RPM? That is the only thing you'd gain by adding the transmission from the GX. So, assuming you didn't change the final drive gearing, you'd be rolling around at 1500rpm or similar at 70mph. Here is the real difference. The UR in the GX460 makes over 240 ft-lb of torque at 1500rpm. The GR in the 4Runner makes around 150 ft-lb (according the the torque curves on the TIS). The GX will actually be able to pull a small incline and stay in 6th gear. The 4Runner would immediately be gearing down to pull any incline at that gear. I've put about 17k miles on my 4Runner and the gearing is already pretty tall. If you were a complete flatlander, you'd probably see a decent fuel economy benefit. I get 24mpg in my 4Runner driving through flatlands in Ohio. Going from 24mpg to 25 or 26mpg saves me practically no money at the gas pumps, though.

The problem then comes to cost. They probably determined that adding the 6AT would add X cost and would only increase sales by Y. Considering the marginal real world efficiency increase, they determined that there wasn't a cost benefit to adding the 6AT. Considering that the yen is so strong against the dollar, that is even more reason to stick with the tried and true 5AT. If they didn't just grab the GX transmission, there would be add'l engineering work in making the ratios properly suit the 1GR. That is extra cost.

As far as reliability, comparing a 6AT and a 5AT of identical designs, the 6AT has more parts and thus has more things that can go wrong. I'm not saying that Toyota's 6AT is unreliable because of it having 6 gears instead of 5. All my research indicates that the 6AT is a very robust transmission. Later in life, though, there are more clutchpacks, brake/clutch pistons, bearings, solenoids, and valves that can go bad. There are just more things that can go wrong from a FMEA perspective.

Now, if the 1GR were direct injection where it made a lot more torque at very low RPM, I could see a real fuel economy benefit coming from another OD gear. As the 6AT is geared now and how the 1GR currently puts out torque makes the 6AT less of a no-brainer when you consider the add'l cost that comes along with it.

I agree adding the exact same tranny from the GX460 would not be ideal considering the gearing with just 6th being an OD. This is why I kept mentioning a "properly engineered and geared" transmission to be used beyond the 5spd. Yes, added costs would incur, but for some consumers an extra 1-2mpg means alot even if it does not to you. It means even more so to each auto manufacturer as the CAFE standards change. We all know Toyota could easily drop in a redesigned 6/7/8 sped tranny in the near future which would offer better fuel economy and performance with no side effects except for possible reliability issues (I doubt). Look at Hyundai/Kia, they just developed their own 6spd tranny in house and use it on some of their small 4cyl compacts On a higher priced vehicle like the 4runner, what makes one think the added costs of R&D cannot be absorbed?

I also agree adding DI would help on all accounts. I truly hope Toyota uses DI on more Toyota models rather than just Lexus. My wifes IS350 motor has excellent low end torque and great HP for a midsize V6.

We have varying opinions, no big deal, we both could be right or wrong

 

[stanleybb50]

Assuming the 5th have the same trans my 4th has, I think 5 is plenty. 6 in the Lexus setup with the v8 and same ratio's plus one higher would be accepatable.

No reason for so many gears... Anything above 6 is ridiculous. Id rather just have a CVT at that point. My goal is usually to shift as little as possible, not have the trans downshift at a tap of the throttle, then upshift when I let off. Would be abnoxious IMO.


Sent from my LS670 using Tapatalk

 

[Quentin]

I agree adding the exact same tranny from the GX460 would not be ideal considering the gearing with just 6th being an OD. This is why I kept mentioning a "properly engineered and geared" transmission to be used beyond the 5spd. Yes, added costs would incur, but for some consumers an extra 1-2mpg means alot even if it does not to you. It means even more so to each auto manufacturer as the CAFE standards change. We all know Toyota could easily drop in a redesigned 6/7/8 sped tranny in the near future which would offer better fuel economy and performance with no side effects except for possible reliability issues (I doubt). Look at Hyundai/Kia, they just developed their own 6spd tranny in house and use it on some of their small 4cyl compacts On a higher priced vehicle like the 4runner, what makes one think the added costs of R&D cannot be absorbed?

I also agree adding DI would help on all accounts. I truly hope Toyota uses DI on more Toyota models rather than just Lexus. My wifes IS350 motor has excellent low end torque and great HP for a midsize V6.

We have varying opinions, no big deal, we both could be right or wrong

Re-engineering a transmission, even something as simple as changing gear ratios, has quite a lot of cost that goes along with it. I am a production engineer for a transmission plant and we fight for pennies on the unit because all those pennies accumulate. Building 2 different versions of the 6AT in one plant is far more expensive than only having to build one. We have several different models now and the only difference is diff ring gear and you'd be shocked at how much extra investment is required for a flexible line (that eventually becomes cost in the transmission). For a lower volume product like the 4Runner, the numbers probably don't work out without showing a price increase.

As far as CAFE, I don't think the 4Runner moves enough units to have a big impact. Since CAFE is volume weighted, and they calculate CAFE using mpg instead of gal/100mi, there is way more impact on the CAFE score if they get the Rav4 up 1 mpg versus the 4Runner. ( C A F E Overview scroll down to see the equation) It makes more sense to get your high volume models up a MPG or two versus what is more of a niche product like the 4Runner.

Now, in the future, the 4Runner will probably get a 6AT. But it would make more sense to spend that money in the future when that transmission is likely attached to an engine that would make better use of the extra gears instead of driving the cost up now with marginal benefit. I would say that the numbers just don't work out to invest in a 6AT for the 4Runner right this moment, especially when 22mpg is really quite good for a 4600lb, 4WD BOF SUV.

 

[SigSense]

Evidently the 2012 Grand Cherokee will sport an eight speed:

http://www.leftlanenews.com/jeep-adds-eight-speed-automatic-to-2012-grand-cherokee.html