2018 200 series vs GX550 (2 Viewers)

[Madtiger]

I can understand your view point and why you say this but I'd offer a different view:

Toyota took a pretty simple/conventional 4x4 drive train, with open differentials, designed for a light duty small pickup aimed at a lower price point market and built the Tacoma. They then added computer aided traction control. Traction control (MTS) allows the mechanical, open diff drive train (yes the off road version has a rear locker) to do things it otherwise couldn't do. MTS does greatly improve the off road performance of truck (especially for 99% of the 10% that actually takes these things off road).

So what happened here? Wy did the diff break? The simple answer is that something in it wasn't strong enough. The next question is why wasn't is strong enough? The answer is, there is a possible use condition that results in overstressing some component in the diff. What caused this condition to exist? The answer is that the MTS logic allowed all the torque to go to one wheel and when that wheel lost traction, the ABS clamped down on it and something broke.

So what's an engineer to do? If the truck didn't have MTS, it likely wouldn't have broke, but it also would likely have not have made it up the hill and would generally perform worse in all off road situations. I would be willing to bet that there were many engineers at Toyota that initially said "lets make the thing that broke stronger". But would doing that result in any actual performance improvement? Would the truck have made it up the hill if it hadn't broke? There's no definitive answer to that. Different line, different driver, lots of factors, who knows. Obviously not blowing up the diff in this situation is more important than making it up the hill, but trying to bullet proof the diff will just lead to finding the next weak link, has risk of its own unintended consequence, would cost a ton, and take a long time time to redesign and build.

IMO, it was the MTS software that killed the diff by allowing a situation to exist that the diff wasn't designed to handle. It allowed too much wheel speed and the ABS to act too quickly and abruptly. The engineers original goal was to tune the system in a way to improve traction performance and not break things. They missed this situation. Had they not missed it, they would have almost certainly tuned the software to protect the diff rather than redesigning the diff. I doubt that whatever software tweaks they made to the MTS system have any significant negative impact to off road performance (I admit this is total assumption). Personally, I'd rather have a software update, even if I lost a little uphill snow wheeling traction control, than a newly designed diff.

So did they use software to to fix under engineering or did they use software to maximize off road performance of an existing mechanical system within its mechanical limits? Both are true, its just perspective. Generally though, an engineer's job is to optimize performance, reliability, cost and schedule in a way that allows the business to make money, and continue to exist. Building the bullet proof brick sh*t house doesn't usually cut it.

Sure except that this was a ground up redesign of Taco with brand new platform. This was not retro-fitting onto old platform.

And IMO, you design software around the hardware. Not the other way around.

 

[kcjaz]

And IMO, you design software around the hardware. Not the other way around.

Agreed. That’s what they did.

 

[skrypj]

Kinda meh on the uphill. Pcm must have been pulling power which is odd considering how cool of a day it was.

 

[TeCKis300]

Kinda meh on the uphill. Pcm must have been pulling power which is odd considering how cool of a day it was.

I dunno man. 9k lbs to 11k elevation is no joke and the rig did the job. Sure, towards the top it lost some oomph, but most every vehicle will. The 200-series being an NA motor will likely lose more power and I've been there in those extreme grades and elevation, pedal to the floor at 50MPH. The funny thing is I'll pull onto a long shoulder to allow single cars to pass, and they don't have the oomph to accelerate and get by me either.

It's not always a race and looks like it'll do the job in 95% of the cases.

The engine braking has me more concerned. Small displacement turbo motors aren't known for very strong engine braking.

 

[skrypj]

I dunno man. 9k lbs to 11k elevation is no joke and the rig did the job. Sure, towards the top it lost some oomph, but most every vehicle will. The 200-series being an NA motor will likely lose more power and I've been there in those extreme grades and elevation, pedal to the floor at 50MPH. The funny thing is I'll pull onto a long shoulder to allow single cars to pass, and they don't have the oomph to accelerate and get by me either.

It's not always a race and looks like it'll do the job in 95% of the cases.

The engine braking has me more concerned. Small displacement turbo motors aren't known for very strong engine braking.

My point is, any of these turbo motors should not have much issue moving a 9000 lb trailer up this hill. There should be power to spare and they should not be flooring it with virtually any trailer. They a generally far more powerful and consistent at these elevations than a V8 and that is the beauty of them. Super casual, effortless towing.

Back in 2013 TFL pulled a 10k lb trailer up the ike with a 6000+ lb 1st gen Ecoboost in 7:36. And the 3rd gen Tundra did not struggle with the same powertrain and gearing on a similar trailer. The tundra never even broke 3200 rpm and they said it had no trouble maintaining speed.

350 hp should be plenty to move a 9000 lb trailer up the hill at 60mph, so it was clearly cutting power. And if you watch when he says he was floored at 14:00 the truck is only at 3600 rpm and isnt even bothering to downshift. Eventually it does downshift and jumps to ~4200 but still should have been able to drop another gear to get up to ~5000 where peak HP is. This is how I would expect our 5.7L's to pull. Not a TTV6 though.

And even the modern V8's dont really have an issue. Heres a 5.3L Chevy(one of the weakest V8's out there) doing it in 8 flat with a 9000 lb enclosed trailer.



Tundra 5.7L Doing 8:18 with a 9000 lb trailer:



I agree on the engine braking, V8's are definately better, but I towed >22000 miles with my 3.5L Ecoboost and it really was not ever an issue,

To be honest, I am a little surprised your argument is not "why get a TTV6 if it doesn't even pull better than our V8's?"

 

[skrypj]

I guess my point was, if you are looking to tow, why drive a more expensive GX550 with a TTV6 than a 200 series 5.7L if there really isnt much benefit?

The whole benefit to these TTV6's is the abundance of low end torque and their ability to compensate for things like elevation and ambient temperature via load based tuning. In theory, no matter what conditions you are driving in, they should be able to make very close to their rated power. My 2014 F150 Ecoboost had much more reserve power than the LX570 does. I could be chugging along in 5th at 2200 rpm and climb small hills even while at 6000+' of elevation without downshifting because it was making close to its maximum 420 ft-lbs at that RPM. Cruising along at 65mph I might only need 320 ft-lbs and so I still had 100 ft-lbs in my back pocket to play with before the truck had to go looking for another gear.

Even when climbing big grades I would generally run in 4th at 3200 rpm and only on the most epic climbs would I need to drop to 3rd at around 4000 rpm, but never needed WOT. It made towing far more relaxing and enjoyable.

The GX550 seems to be operating like a V8 and not actually compensating for elevation. If I had to take a wild guess, its only making about 250hp near the top or about a 30% loss in power, exactly what the air pressure loss is. Heres a video of a 260hp/480ft-lbs Ram Ecodiesel that was towing a 8700 lb trailer and ran nearly the same time as the GX.



So I think my 250hp estimate is probably pretty close. Thats a major loss in power from a TTV6. If this thing was making its peak 479 ft-lbs at 3600 rpm when he said it was floored(the GX spec sheet says 479 is available from 2000 to 3600 rpm) then this thing would have been putting out nearly 330hp, but it seems like it was more like 370 ft-lbs.

 

[TeCKis300]

I guess my point was, if you are looking to tow, why drive a more expensive GX550 with a TTV6 than a 200 series 5.7L if there really isnt much benefit?

The whole benefit to these TTV6's is the abundance of low end torque and their ability to compensate for things like elevation and ambient temperature via load based tuning. In theory, no matter what conditions you are driving in, they should be able to make very close to their rated power. My 2014 F150 Ecoboost had much more reserve power than the LX570 does. I could be chugging along in 5th at 2200 rpm and climb small hills even while at 6000+' of elevation without downshifting because it was making close to its maximum 420 ft-lbs at that RPM. Even when climbing big grades I would generally run in 4th at 3200 rpm and only on the most epic climbs would I need to drop to 3rd at around 4000 rpm, but never needed WOT.

The GX seems to be operating like a V8 and not actually compensating for elevation. If I had to take a wild guess its only making about 250hp near the top or about a 30% loss in power, exactly what the air pressure loss is. Heres a video of a 260hp/480ft-lbs Ram Ecodiesel that was towing a 8700 lb trailer and ran nearly the same time as the GX.



So I think my 250hp estimate is probably pretty close. Thats a SIGNIFICANT loss in power from a TTV6.

I don't disagree with most of your points. I have no real interest in the GX550, and maybe we agree, the 200-series is the superior vehicle. It makes more rated HP after all. Not all TT-V6s are equal and depends on tuning and turbo sizing, the GX550 is probably more a low/midrange and response based configuration, than a HP monster. Both the Tundra and LX600 with the same engine are rated for more output, probably with some boost, cooling, and turbo tweaks.

Context is important.

I think your experience with the Ford really doesn't apply. It's a lighter vehicle than these GXs/LXs, at upwards of 1000+ lbs more curb weight. The F150 is also primarily 2WD compared to full time 4WD. AT tires also matter. Rolled up, these are big differences and factors to perceived output and performance. Your experience is also borne from towing ~5.5k lbs IIRC. That a far cry from 9k lbs in this review. Same with engine braking...on the Airstream forums, people towing on the upper end of the spectrum complain all the time about the F150s poor engine braking.

Agreed the shifting logic could have done better to better optimize the powerband and engine braking. When towing, I tend to use manual/sport mode as the driver can better anticipate.

For a 349 HP rated GX550, it did well.

 

[skrypj]

I don't disagree with most of your points. I have no real interest in the GX550, and maybe we agree, the 200-series is the superior vehicle. It makes more rated HP after all. Not all TT-V6s are equal and depends on tuning and turbo sizing, the GX550 is probably more a low/midrange and response based configuration, than a HP monster. Both the Tundra and LX600 with the same engine are rated for more output, probably with some boost, cooling, and turbo tweaks.

I guess its all just in the expectations

I am genuinely curious if the LX600 motor or turbos are physically different. The LX600 has a lower tow rating despite the extra 60 hp. I wonder if TFL could ever get one and run the same test.

The GX is fine as you say, but it certainly didnt meet my expectations of it, knowing the powertrain. As someone who has owned and towed with a TTV6 truck for >20000 miles, my expectation was that this GX was going to maintain power and torque like any other turbo truck motor does.

My F150 did not maintain 100% torque up to 11,000' of elevation but it didnt lose 30% either. Even at 11,000' it was still making >90% of its rated torque between 2500-3700 rpm. A GX550 making 90% of its peak torque still be putting out a solid 430 ft-lbs, which is a lot.

I think your experience with the Ford really doesn't apply. It's a lighter vehicle than these GXs/LXs, at upwards of 1000+ lbs more curb weight. The F150 is also primarily 2WD compared to full time 4WD. AT tires also matter. Rolled up, these are big differences and factors to perceived output and performance. Your experience is also borne from towing ~5.5k lbs IIRC. That a far cry from 9k lbs in this review. Same with engine braking...on the Airstream forums, people towing on the upper end of the spectrum complain all the time about the F150s poor engine braking.

Agreed the shifting logic could have done better to better optimize the powerband and engine braking. When towing, I tend to use manual/sport mode as the driver can better anticipate.

For a 349 HP rated GX550, it did well.

The new GX550 Overtrail is 5500 lbs per the Lexus spec sheet. Car and Driver scaled theirs at 5517. Even the LX is like 5600 lbs.

And I did not have a fancy new aluminum F150. Mine was the steel body and was at least 6400 lbs. Its empty curb weight was 6160 lbs(confirmed by cat scale and the payload sticker) and with my fiberglass Leer topper and all the other things I had bolted on it was easily at 6400 with nothing in it. It was turning 315/70R17 KO2's. Fully loaded up with my family of 4, 2 dogs, and all the crap we put in the truck, I bet it was pushing 7400 lbs.

I am not going to claim my GCWR was as high as this GX550's was, but I bet its not as far off as you think with my truck and trailer loaded down for camping. And I bet my trailer is a lot less aerodynamic at 60mph than a chevy colorado on a car trailer.

And my point was not to compare my F150 to the GX550, but to my LX570, which has towed the same trailer and been loaded down with the same people and gear. Its also on 35's. I've towed 3500 miles on my LX so I have pretty good feel for it at this point. If the GX550 is going to pull similar to the LX570, then I am glad I went with an LX and didn't wait around for a GX, was all I was saying. To me, the main benefit of the GX550 would have been the effortless torque at low RPM.

 

[TeCKis300]

I guess its all just in the expectations

I am genuinely curious if the LX600 motor or turbos are physically different. The LX600 has a lower tow rating despite the extra 60 hp. I wonder if TFL could ever get one and run the same test.

The GX is fine as you say, but it certainly didnt meet my expectations of it, knowing the powertrain. As someone who has owned and towed with a TTV6 truck for >20000 miles, my expectation was that this GX was going to maintain power and torque like any other turbo truck motor does.

My F150 did not maintain 100% torque up to 11,000' of elevation but it didnt lose 30% either. Even at 11,000' it was still making >90% of its rated torque between 2500-3700 rpm. A GX550 making 90% of its peak torque still be putting out a solid 430 ft-lbs, which is a lot.



The new GX550 Overtrail is 5500 lbs per the Lexus spec sheet. Car and Driver scaled theirs at 5517. Even the LX is like 5600 lbs.

And I did not have a fancy new aluminum F150. Mine was the steel body and was at least 6400 lbs. Its empty curb weight was 6160 lbs(confirmed by cat scale and the payload sticker) and with my fiberglass Leer topper and all the other things I had bolted on it was easily at 6400 with nothing in it. It was turning 315/70R17 KO2's. Fully loaded up with my family of 4, 2 dogs, and all the crap we put in the truck, I bet it was pushing 7400 lbs.

I am not going to claim my GCWR was as high as this GX550's was, but I bet its not as far off as you think with my truck and trailer loaded down for camping. And I bet my trailer is a lot less aerodynamic at 60mph than a chevy colorado on a car trailer.

And my point was not to compare my F150 to the GX550, but to my LX570, which has towed the same trailer and been loaded down with the same people and gear. Its also on 35's. I've towed 3500 miles on my LX so I have pretty good feel for it at this point. If the GX550 is going to pull similar to the LX570, then I am glad I went with an LX and didn't wait around for a GX, was all I was saying. To me, the main benefit of the GX550 would have been the effortless torque at low RPM.

Interesting that the LX600 has a lower tow rating. It's probably not power or cooling. Probably suspension (spring rates) if I had to guess.

You probably know but just saying out loud, torque is great for getting off the line. But it is HP that defines performance in towing loads to the top of mountains. So while the GX has a great torque rating, it's still only 349 HP. It's performance on the Ike fits pretty well with that.

 

[skrypj]

Interesting that the LX600 has a lower tow rating. It's probably not power or cooling. Probably suspension (spring rates) if I had to guess.

You probably know but just saying out loud, torque is great for getting off the line. But it is HP that defines performance in towing loads to the top of mountains. So while the GX has a great torque rating, it's still only 349 HP. It's performance on the Ike fits pretty well with that.

Right, it performed in line with a 349hp NA V8. Or a 260 hp 3.0L Ecodiesel. I posted the video above.