Hello everyone. Just to give some credentials (and I will give sources as I go) I have owned every single camry since 1995. I have owned a 2018 SE and own a 2019 XSE (and also have or had multiple lexus vehicles including a new IS350). I have worked on all of them and usually do stupid amounts of research on every car I buy (hence why I do not have a new accord but do intend to keep my v6 coupe for a while). Based on my research as well as digging under the hood of my own cars, I have enough knowledge to make a few conclusions, find some correlations, and develop a theory. Here it goes.
First and foremost, the trans. I feel like this transmission gets a bad rep because of the fact that it is a bit laggy. This is toyota's tuning. Toyota is tuning the engine for maximum efficiency to pass EPA emissions tests in the new era of restrictions, which, if it didn't, it would fail and not pass with its dated but reliable engines. The other thing is the shudder/jerkiness. This is because of the torque converter lockup (also done for emissions, as at idle/cruising speed in what ever gear you are doing, the torque converter locks up to make it more like a manual and get that extra 1mpg). This torque converter lock up can be seen watching the RPM needle and/or using a laptop to read the RPM from the ECU as it falls 100-150 rpm when the torque converter locks up after the trans settles. It is also tuned to lock up when at full throttle, to give a more "sporty" and more "direct" feel of the trans. This is why some people experience a shudder and why toyota thinks this is a non issue. Most people want a smooth transmission. This one is not going to do that. It is made to be this way using a larger and thicker clutchpack within the torque converter to induce faster, more reliable lockup at more gears (in this transmission from 2nd to 8th) meaning you are getting really close to a DSG without actually using a DSG transmission. Here is their own info: New 8-speed and 10-speed Automatic Transmissions (Direct Shift-8AT & Direct Shift-10AT) | Toyota Motor Corporation Official Global Website
I asked a few of my buddies that work on cars as hobbies like I do to comment, and most of them after looking at some schematics and videos, seem to agree that this is what toyota considers a happy medium between a DSG/Single clutch auto and a traditional torque converted auto. The issue now is tuning, which I highly recommend you to get done if possible, as this improves the transmission response a LOT (warning, this will make you feel said lock up a lot more). Drove my friends DSG VW and it felt about the same with noticeable "hesitation" (which isn't hesitation, its simply inconsistency in driver input). Once I got used to the throttle there were no problems on the VW, same with my camry. I actually find that people who care less about the throttle don't have this problem (like my mom or sister who aren't particularly sharp when it comes to cars). They just put their foot where ever they think its needed and it goes, the transmission doesn't have to change its mind every 0.1 seconds.
Next up, the engine. Its handicapped. Now I am sure this isn't a surprise. But let me explain.
The engine can easily make a bunch more power, but there are 3 main constraints on the engine. 1) the cooled-EGR system, 2) The fuel map and 3) Traction control.
Lets start with #3. Traction control is the easiest to understand. The 4 banger (let alone the v6) will shred tires. This is due to the open differential Toyota uses. Adding a limited slip diff (and on AWD models, using a true AWD system) would hurt efficiency and also cost several thousand on top of the existing cost of the car. This would also disbalance the front end even more especially on the v6 models. So toyota just doesn't do anything about it. But since it's marketing its new camry as "sporty", there are a lot of people who take that marketing without salt and therefore are disappointed.
#1. Cooled EGR. Now there is very little documentation on this system. The EPA did some benchmarking and has some good cad schematics and layouts of how/where this system works. (https://www.epa.gov/sites/production/files/2020-08/documents/sae-2019-01-0249.pdf). If you look at the drawing of the catalytic converter, its the little tail that sticks out with the #1 on it : 2019 Toyota Camry Catalytic Converter (Front). Pipe, Exhaust - 174100P380 - Genuine Toyota Part. So ELI5 on how this works. The engine creates exhaust gasses, and without this system, toyota would not pass new emissions tests. So it used this system. The way it works in the camry, is it has a valved muffler, which creates backpressure into the exhaust, forcing some gasses up this little tail back into the engine. This reduces the amount of fuel the engine uses (because it reads the air coming into the engine TWICE, at the MAF sensor and there is another one at the engine block (yay more electronics). Combined it gets a combined reading for the o2 content and uses less gas. This is why the XSE with the dual mufflers creates more power (slightly), it has more air coming out making less back pressure and relying on this system less (I still got 42MPG average in my XSE on the way to VA from SC). This is also confirmed on my ES350 and my IS350. The IS350 makes a little bit more power (10hp) compared to my ES. This is because the ES uses said scavenging system, and the IS does not. I wish I took some pictures when the car was on the lift at my buddies shop but alas I did not. But on the shematics this system is not present (EXHAUST PIPE. Lexus IS 350 | Lexus Parts & Accessories Online) and there are also no EPA tests on that engine. This system is present on the v6, but it seems to be a pick and choose system depending on the car (camry, avalon and ES have it, IS and GS do not).
This system can be mitigated fairly easily. Just remove the cats (and or just seal off the little tube but cutting it and welding it closed). Then replace the muffler with a non valved muffler and put a cold air intake on the car. This will allow you to get 100% outside air into the engine, and having less back pressure, making more power. From what I have seen on the DYNO and places online, its between a 10 and 20 hp gain. Not bad! But this isn't everything. This leads me into the fuel map.
#2. This engine's fuel map is primarily designed for the above EGR system with 87 octane. Why? Well EGR also reduces knock by retarding the explosion in your cylinders. This is a 13:1 (and 13.5:1 on the hybrid) engine, which in all my years working on cars, means that it needs to run 91+ octane. But for some reason, using 91 octane yields no power increase. Again, this is due to the fuel map depending on said EGR system. Now sure, the ECU is smart enough to adapt the fuel map to different fuel types, and you might see a 1hp gain, but, if you remove the EGR system, and you still run 87 octane (or even 89), I doubt your engine will last. Sure, the VVTI system is smart enough to try to reduce knock as much as possible, but trust my experience, this is simply delaying the inevitable. So please, run 91 or 93 octane if you have removed the EGR system (AKA new exhaust from cat back, if you simply removed the mufflers you are "okay" but you are creating less back pressure so I would run 89 octane). Also go to your local tune shop with a full tank of 91/93 and get it tuned. This will reduce wear on your engine, and probably make more power (I have seen close to 25% gains with a 91 octane tune with free flow exhaust and intake). There is no source for this other than that this is a known thing in the auto community, anything over 11:1 you should be using high octane fuel. If your car (let's say its not a toyota) has a high compression engine and you run 87 because that is what the manual tells you, you most likely have EGR with a 87 octane fuel map.
Well, thats about it. This has been on the my mind for a while (about 2017 when this stuff was being announced/leaked). A lot of this stuff made no sense, like 87 octane on 13:1, increasing HP without increasing fuel consumption, reports of torque converter shudder (its not shudder, its normal, this isnt like my 2014 that had the trans replaced under warranty). This is mostly all theory based on information. I simply collected knowledge and made inferences. So I may be wrong, but I doubt it.
First and foremost, the trans. I feel like this transmission gets a bad rep because of the fact that it is a bit laggy. This is toyota's tuning. Toyota is tuning the engine for maximum efficiency to pass EPA emissions tests in the new era of restrictions, which, if it didn't, it would fail and not pass with its dated but reliable engines. The other thing is the shudder/jerkiness. This is because of the torque converter lockup (also done for emissions, as at idle/cruising speed in what ever gear you are doing, the torque converter locks up to make it more like a manual and get that extra 1mpg). This torque converter lock up can be seen watching the RPM needle and/or using a laptop to read the RPM from the ECU as it falls 100-150 rpm when the torque converter locks up after the trans settles. It is also tuned to lock up when at full throttle, to give a more "sporty" and more "direct" feel of the trans. This is why some people experience a shudder and why toyota thinks this is a non issue. Most people want a smooth transmission. This one is not going to do that. It is made to be this way using a larger and thicker clutchpack within the torque converter to induce faster, more reliable lockup at more gears (in this transmission from 2nd to 8th) meaning you are getting really close to a DSG without actually using a DSG transmission. Here is their own info: New 8-speed and 10-speed Automatic Transmissions (Direct Shift-8AT & Direct Shift-10AT) | Toyota Motor Corporation Official Global Website
I asked a few of my buddies that work on cars as hobbies like I do to comment, and most of them after looking at some schematics and videos, seem to agree that this is what toyota considers a happy medium between a DSG/Single clutch auto and a traditional torque converted auto. The issue now is tuning, which I highly recommend you to get done if possible, as this improves the transmission response a LOT (warning, this will make you feel said lock up a lot more). Drove my friends DSG VW and it felt about the same with noticeable "hesitation" (which isn't hesitation, its simply inconsistency in driver input). Once I got used to the throttle there were no problems on the VW, same with my camry. I actually find that people who care less about the throttle don't have this problem (like my mom or sister who aren't particularly sharp when it comes to cars). They just put their foot where ever they think its needed and it goes, the transmission doesn't have to change its mind every 0.1 seconds.
Next up, the engine. Its handicapped. Now I am sure this isn't a surprise. But let me explain.
The engine can easily make a bunch more power, but there are 3 main constraints on the engine. 1) the cooled-EGR system, 2) The fuel map and 3) Traction control.
Lets start with #3. Traction control is the easiest to understand. The 4 banger (let alone the v6) will shred tires. This is due to the open differential Toyota uses. Adding a limited slip diff (and on AWD models, using a true AWD system) would hurt efficiency and also cost several thousand on top of the existing cost of the car. This would also disbalance the front end even more especially on the v6 models. So toyota just doesn't do anything about it. But since it's marketing its new camry as "sporty", there are a lot of people who take that marketing without salt and therefore are disappointed.
#1. Cooled EGR. Now there is very little documentation on this system. The EPA did some benchmarking and has some good cad schematics and layouts of how/where this system works. (https://www.epa.gov/sites/production/files/2020-08/documents/sae-2019-01-0249.pdf). If you look at the drawing of the catalytic converter, its the little tail that sticks out with the #1 on it : 2019 Toyota Camry Catalytic Converter (Front). Pipe, Exhaust - 174100P380 - Genuine Toyota Part. So ELI5 on how this works. The engine creates exhaust gasses, and without this system, toyota would not pass new emissions tests. So it used this system. The way it works in the camry, is it has a valved muffler, which creates backpressure into the exhaust, forcing some gasses up this little tail back into the engine. This reduces the amount of fuel the engine uses (because it reads the air coming into the engine TWICE, at the MAF sensor and there is another one at the engine block (yay more electronics). Combined it gets a combined reading for the o2 content and uses less gas. This is why the XSE with the dual mufflers creates more power (slightly), it has more air coming out making less back pressure and relying on this system less (I still got 42MPG average in my XSE on the way to VA from SC). This is also confirmed on my ES350 and my IS350. The IS350 makes a little bit more power (10hp) compared to my ES. This is because the ES uses said scavenging system, and the IS does not. I wish I took some pictures when the car was on the lift at my buddies shop but alas I did not. But on the shematics this system is not present (EXHAUST PIPE. Lexus IS 350 | Lexus Parts & Accessories Online) and there are also no EPA tests on that engine. This system is present on the v6, but it seems to be a pick and choose system depending on the car (camry, avalon and ES have it, IS and GS do not).
This system can be mitigated fairly easily. Just remove the cats (and or just seal off the little tube but cutting it and welding it closed). Then replace the muffler with a non valved muffler and put a cold air intake on the car. This will allow you to get 100% outside air into the engine, and having less back pressure, making more power. From what I have seen on the DYNO and places online, its between a 10 and 20 hp gain. Not bad! But this isn't everything. This leads me into the fuel map.
#2. This engine's fuel map is primarily designed for the above EGR system with 87 octane. Why? Well EGR also reduces knock by retarding the explosion in your cylinders. This is a 13:1 (and 13.5:1 on the hybrid) engine, which in all my years working on cars, means that it needs to run 91+ octane. But for some reason, using 91 octane yields no power increase. Again, this is due to the fuel map depending on said EGR system. Now sure, the ECU is smart enough to adapt the fuel map to different fuel types, and you might see a 1hp gain, but, if you remove the EGR system, and you still run 87 octane (or even 89), I doubt your engine will last. Sure, the VVTI system is smart enough to try to reduce knock as much as possible, but trust my experience, this is simply delaying the inevitable. So please, run 91 or 93 octane if you have removed the EGR system (AKA new exhaust from cat back, if you simply removed the mufflers you are "okay" but you are creating less back pressure so I would run 89 octane). Also go to your local tune shop with a full tank of 91/93 and get it tuned. This will reduce wear on your engine, and probably make more power (I have seen close to 25% gains with a 91 octane tune with free flow exhaust and intake). There is no source for this other than that this is a known thing in the auto community, anything over 11:1 you should be using high octane fuel. If your car (let's say its not a toyota) has a high compression engine and you run 87 because that is what the manual tells you, you most likely have EGR with a 87 octane fuel map.
Well, thats about it. This has been on the my mind for a while (about 2017 when this stuff was being announced/leaked). A lot of this stuff made no sense, like 87 octane on 13:1, increasing HP without increasing fuel consumption, reports of torque converter shudder (its not shudder, its normal, this isnt like my 2014 that had the trans replaced under warranty). This is mostly all theory based on information. I simply collected knowledge and made inferences. So I may be wrong, but I doubt it.
