Awful Gas Mileage and Range
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Joined: May 2009
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From: GA
Not trying to correct you, just helping out with some facts. The stated HP of the gas engine in the 450h is 275hp (what the 2010-2012 350's were rated at), then add the 20 from the electric motors and it goes to 295. So the earlier Gen III RX350's had the same HP as the RX450h minus the hybrid power.
What I haven't figured out is how both the FWD and the AWD hybrids are rated the same in total hp as the AWD have two additional electric motors in the rear.
What I haven't figured out is how both the FWD and the AWD hybrids are rated the same in total hp as the AWD have two additional electric motors in the rear.
Compression ratio is a statically calculated mechanical ratio of cylinder volume to combustion chamber volume, but the Atkinson cycle is designed NOT to take a full intake charge into the cylinder, so in everyday use the realized compression is not quite so high as might seem to be indicated. That is why these engines (even though specification wise are a higher compression engine normally associated with higher performance engines) don't develop as much torque or HP as their conventional twins. They burn cleaner and more efficiently, and rely on the electric motors to add back the missing torque and HP.
If you take a regular RX350 motor, up it's compression to 12.5 and throw in some electric motors, now that would be awesome, they'd have to call in an RX600h.
If you take a regular RX350 motor, up it's compression to 12.5 and throw in some electric motors, now that would be awesome, they'd have to call in an RX600h.
Last edited by Cruiter; Apr 8, 2013 at 05:29 PM.
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Joined: Dec 2012
Posts: 2,147
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From: Toronto, ON
Not trying to correct you, just helping out with some facts. The stated HP of the gas engine in the 450h is 275hp (what the 2010-2012 350's were rated at), then add the 20 from the electric motors and it goes to 295. So the earlier Gen III RX350's had the same HP as the RX450h minus the hybrid power.
What I haven't figured out is how both the FWD and the AWD hybrids are rated the same in total hp as the AWD have two additional electric motors in the rear.
What I haven't figured out is how both the FWD and the AWD hybrids are rated the same in total hp as the AWD have two additional electric motors in the rear.
Its just that the specs I've seen rate the 450 engine as 245HP from a couple of different unofficial sources, with a 50HP boose from the hybrid system. Not sure how reliable, because Toyota/Lexus no longer like to publish specs of the engine separately, only a system total (which I guess they think is less confusing to most buyers).
I know on my old 2007 Camry Hybrd (back when Toyota freely published engine specs separately), the 4 cyl atkinson engine produced 147HP (158HP for the standard engine), and the hybrid system added 40HP. I would be a little surprised that the Camry battery could add 40HP and the RXh battery was only able to add 20HP to the total system output.
The reason the FWD and AWD model have the same total HP is that the number and power of the electric motors is not the limiting factor, it is the maximum output of the battery that governs the HP boost, and its the same for FWD and AWD.
Thread Starter
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Joined: Nov 2012
Posts: 228
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From: USA
Your right about the premium requirement for 2011's and older models of the RX 350/330.
There was no change in the engine.
However, there's a decrease in the "claimed" horsepower.
If i remember the sticker correctly, my 2011 promises 275 hp on premium fuel while your 2012/2013 have 270hp on regular unleaded. Again, it's still the same engine.
I'm pretty sure some tweaking were made to accomodate the change in fuel.
Anyway, i don't really pay attention to the horsepower, im more interested with the torque which is a better gauge of power. And how's the torque at 2,000, 3,000 or even 4,000 rpm. But this deserves a different thread and another day of discussion.
There was no change in the engine.
However, there's a decrease in the "claimed" horsepower.
If i remember the sticker correctly, my 2011 promises 275 hp on premium fuel while your 2012/2013 have 270hp on regular unleaded. Again, it's still the same engine.
I'm pretty sure some tweaking were made to accomodate the change in fuel.
Anyway, i don't really pay attention to the horsepower, im more interested with the torque which is a better gauge of power. And how's the torque at 2,000, 3,000 or even 4,000 rpm. But this deserves a different thread and another day of discussion.
Last edited by satnav; Apr 8, 2013 at 08:36 PM.
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Joined: May 2009
Posts: 2,838
Likes: 26
From: GA
Well even I learn from my own research. I had thought the de-tuning so to speak of the 2013 350 reduced it's hp a tad based on posts here. According to the chart below, it's still 270 as in 2010-2012. But the compression ratio that used to be the same is definitely lower. Maybe someone has an older chart to share ??? I never quote from a chart that isn't from Lexus, if there is to be a 'standard' to go by, then I'd use that. I've never seen the hybrid boost more than 20hp but that's still a considerable difference.
I forgot to insert the latest chart, oops
I forgot to insert the latest chart, oops
I don't mind being corrected, the truth will set you free
Its just that the specs I've seen rate the 450 engine as 245HP from a couple of different unofficial sources, with a 50HP boose from the hybrid system. Not sure how reliable, because Toyota/Lexus no longer like to publish specs of the engine separately, only a system total (which I guess they think is less confusing to most buyers).
I know on my old 2007 Camry Hybrd (back when Toyota freely published engine specs separately), the 4 cyl atkinson engine produced 147HP (158HP for the standard engine), and the hybrid system added 40HP. I would be a little surprised that the Camry battery could add 40HP and the RXh battery was only able to add 20HP to the total system output.
The reason the FWD and AWD model have the same total HP is that the number and power of the electric motors is not the limiting factor, it is the maximum output of the battery that governs the HP boost, and its the same for FWD and AWD.
Its just that the specs I've seen rate the 450 engine as 245HP from a couple of different unofficial sources, with a 50HP boose from the hybrid system. Not sure how reliable, because Toyota/Lexus no longer like to publish specs of the engine separately, only a system total (which I guess they think is less confusing to most buyers).
I know on my old 2007 Camry Hybrd (back when Toyota freely published engine specs separately), the 4 cyl atkinson engine produced 147HP (158HP for the standard engine), and the hybrid system added 40HP. I would be a little surprised that the Camry battery could add 40HP and the RXh battery was only able to add 20HP to the total system output.
The reason the FWD and AWD model have the same total HP is that the number and power of the electric motors is not the limiting factor, it is the maximum output of the battery that governs the HP boost, and its the same for FWD and AWD.
Last edited by Cruiter; Apr 9, 2013 at 06:03 AM.
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Joined: Dec 2012
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From: Toronto, ON
I tried to trace back where the unofficial sources (car review websites) got their information about the 245HP / 295HP rating, it seems to have originated with this Lexus press release.
http://pressroom.lexus.com/article_d...rticle_id=1616
It discusses the difference in engines, HP, torque, total system power, etc. between the RX400h and the "new" RX450h.
http://pressroom.lexus.com/article_d...rticle_id=1616
It discusses the difference in engines, HP, torque, total system power, etc. between the RX400h and the "new" RX450h.
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Joined: May 2009
Posts: 2,838
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From: GA
Yea, that was before the car actually came out. The 1st production models were manufactured in May of 09 (I got one of those and it's a great car). I just inserted the chart I forgot in my previous post.
I tried to trace back where the unofficial sources (car review websites) got their information about the 245HP / 295HP rating, it seems to have originated with this Lexus press release.
http://pressroom.lexus.com/article_d...rticle_id=1616
It discusses the difference in engines, HP, torque, total system power, etc. between the RX400h and the "new" RX450h.
http://pressroom.lexus.com/article_d...rticle_id=1616
It discusses the difference in engines, HP, torque, total system power, etc. between the RX400h and the "new" RX450h.
Lexus Test Driver
Joined: Aug 2011
Posts: 1,068
Likes: 11
From: California
@ Cruiter..
"Well even I learn from my own research. I had thought the de-tuning so to speak of the 2013 350 reduced it's hp a tad based on posts here. According to the chart below, it's still 270 as in 2010-2012"
NOPE!
the 2011 RX 350 ( and older ) hp is 275
http://www.edmunds.com/lexus/rx-350/...101353967&sub=
2012 RX 350 ( and newer) is 270
http://www.edmunds.com/lexus/rx-350/...style=&sub=suv
i KNOW personally that the sticker on my window says 275hp..
the decrease can be easily explained by the fuel requirement change.. from premium to regular unleaded
anybody else who owns a 2010-2011 RX 350? care to join the issue
and who drives at 6200 rpm anyway??
"Well even I learn from my own research. I had thought the de-tuning so to speak of the 2013 350 reduced it's hp a tad based on posts here. According to the chart below, it's still 270 as in 2010-2012"
NOPE!
the 2011 RX 350 ( and older ) hp is 275
http://www.edmunds.com/lexus/rx-350/...101353967&sub=
2012 RX 350 ( and newer) is 270
http://www.edmunds.com/lexus/rx-350/...style=&sub=suv
i KNOW personally that the sticker on my window says 275hp..
the decrease can be easily explained by the fuel requirement change.. from premium to regular unleaded
anybody else who owns a 2010-2011 RX 350? care to join the issue
and who drives at 6200 rpm anyway??
Last edited by markrivers; Apr 9, 2013 at 06:22 AM.
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Joined: Dec 2012
Posts: 2,147
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From: Toronto, ON
Mine was built late in July 09 I like to think I got the very last RX sunglass holder 
I'll sell it separately to anyone for $10,000, just send me a PM. 
Yea, I see your chart. That's the problem now with Lexus/Toyota. They stopped publishing the power output of the engine separately, only total power for hybrids. Marketing people got involved with this, they only want casual buyers to know that the hybrid has more total HP than their non-hybrid twin. They don't want to confuse people with a separately published engine HP rating that is less. You can't infer from the chart that the 270HP 2GR-FE RX350 engine is going to have the same output as the 2GR-FXE in the 450, because while related, it is a different engine.
ADD: I think I've gotten a bit obsessed with finding some actual Lexus numbers to compare just to see exactly what is different, so I continued hunting. These are the specific differences between the 350 and 450 engine only specifications for the 2013 model from Lexus pressroom website.
Engine Code: 2GR-FE vs 2GR-FXE
Horsepower: 270HP @ 6,200rpm vs 245HP @ 6,000rpm
Torque: 248 lb-ft@ 4,700rpm vs 234 lb-ft @ 4,800rpm
Compression Ratio: 10.8:1 vs 12.5: 1
Redline: 6,400 rpm vs 6,200 rpm
The 350 numbers are based on 87 octaine, the 450 numbers are based on 91 octane.
I like to think I got the very last RX sunglass holder I'll sell it separately to anyone for $10,000, just send me a PM. Yea, I see your chart. That's the problem now with Lexus/Toyota. They stopped publishing the power output of the engine separately, only total power for hybrids. Marketing people got involved with this, they only want casual buyers to know that the hybrid has more total HP than their non-hybrid twin. They don't want to confuse people with a separately published engine HP rating that is less. You can't infer from the chart that the 270HP 2GR-FE RX350 engine is going to have the same output as the 2GR-FXE in the 450, because while related, it is a different engine.
ADD: I think I've gotten a bit obsessed with finding some actual Lexus numbers to compare just to see exactly what is different, so I continued hunting. These are the specific differences between the 350 and 450 engine only specifications for the 2013 model from Lexus pressroom website.
Engine Code: 2GR-FE vs 2GR-FXE
Horsepower: 270HP @ 6,200rpm vs 245HP @ 6,000rpm
Torque: 248 lb-ft@ 4,700rpm vs 234 lb-ft @ 4,800rpm
Compression Ratio: 10.8:1 vs 12.5: 1
Redline: 6,400 rpm vs 6,200 rpm
The 350 numbers are based on 87 octaine, the 450 numbers are based on 91 octane.
Last edited by Droid13; Apr 9, 2013 at 06:57 AM.
Lexus Test Driver
Joined: Mar 2013
Posts: 838
Likes: 2
From: Ohio
According to Mechanical Engineering theory, to reduce Compression ratio will not affect much in lower HP range. Thought it will allow you to burn Lower Grade Gasoline safer or to Force Induce the engine better.
HP will only count at high Speed, when your car gains enough Momentum, to keep on Accelerating. Torque is what get your car going from the Stop point, it is a Twisted Force + Fraction to Push your car Foward. According to this, the Heavier the Vehicle, the More Torque it needs to Gain Momentum faster.
For all that said, You can have better MPG by two simple things. Better Air flow (Air Filter) + Better Tires. People Often Under Rated how important it is that their Tires + Wheels Diameter affecting their MPG.
For Example, Oversized + Slim profile Tires = More Gasoline Wasted to get the car going at Stop Point, also at Accelerating. Because it simple has not enough Air inside to creates sufficient fraction, and this means the Engine needs to work harder. How about you try running Bare foot vs Aired Sneaker person ? That is what I mean (Less cushion, less Comfort, can not be as Efficient)
Though, I dont normally recommend the use of After Market Air Filter. Because it free up more space, that mean more FINE DUST Will have better chance at getting into your Engine. The best Air Filter for RELIABILITY is the Paper one, encased inside a plastic box, which your car was ENGINEERED for. The After Market will bring in better Small Margin MPG + Engine Respond, and more HP, but also reduce your engine Life by a Small Margin. But usually if you don't want to keep your car for 500,000 miles or 100 years....you shouldn't care
Conclusion, the only thing that does not Affect your Guarantee/Warranty from the factory is the Tires. Buy better tires, and running 18" on your RX350 = better of both world. More MPG, More comfort ability, but...well....increased Body ROLL.....LOL
HP will only count at high Speed, when your car gains enough Momentum, to keep on Accelerating. Torque is what get your car going from the Stop point, it is a Twisted Force + Fraction to Push your car Foward. According to this, the Heavier the Vehicle, the More Torque it needs to Gain Momentum faster.
For all that said, You can have better MPG by two simple things. Better Air flow (Air Filter) + Better Tires. People Often Under Rated how important it is that their Tires + Wheels Diameter affecting their MPG.
For Example, Oversized + Slim profile Tires = More Gasoline Wasted to get the car going at Stop Point, also at Accelerating. Because it simple has not enough Air inside to creates sufficient fraction, and this means the Engine needs to work harder. How about you try running Bare foot vs Aired Sneaker person ? That is what I mean (Less cushion, less Comfort, can not be as Efficient)
Though, I dont normally recommend the use of After Market Air Filter. Because it free up more space, that mean more FINE DUST Will have better chance at getting into your Engine. The best Air Filter for RELIABILITY is the Paper one, encased inside a plastic box, which your car was ENGINEERED for. The After Market will bring in better Small Margin MPG + Engine Respond, and more HP, but also reduce your engine Life by a Small Margin. But usually if you don't want to keep your car for 500,000 miles or 100 years....you shouldn't care
Conclusion, the only thing that does not Affect your Guarantee/Warranty from the factory is the Tires. Buy better tires, and running 18" on your RX350 = better of both world. More MPG, More comfort ability, but...well....increased Body ROLL.....LOL
@ Cruiter..
"Well even I learn from my own research. I had thought the de-tuning so to speak of the 2013 350 reduced it's hp a tad based on posts here. According to the chart below, it's still 270 as in 2010-2012"
NOPE!
the 2011 RX 350 ( and older ) hp is 275
http://www.edmunds.com/lexus/rx-350/...101353967&sub=
2012 RX 350 ( and newer) is 270
http://www.edmunds.com/lexus/rx-350/...style=&sub=suv
i KNOW personally that the sticker on my window says 275hp..
the decrease can be easily explained by the fuel requirement change.. from premium to regular unleaded
anybody else who owns a 2010-2011 RX 350? care to join the issue
and who drives at 6200 rpm anyway??
"Well even I learn from my own research. I had thought the de-tuning so to speak of the 2013 350 reduced it's hp a tad based on posts here. According to the chart below, it's still 270 as in 2010-2012"
NOPE!
the 2011 RX 350 ( and older ) hp is 275
http://www.edmunds.com/lexus/rx-350/...101353967&sub=
2012 RX 350 ( and newer) is 270
http://www.edmunds.com/lexus/rx-350/...style=&sub=suv
i KNOW personally that the sticker on my window says 275hp..
the decrease can be easily explained by the fuel requirement change.. from premium to regular unleaded
anybody else who owns a 2010-2011 RX 350? care to join the issue
and who drives at 6200 rpm anyway??
Lexus Test Driver
Joined: Mar 2013
Posts: 838
Likes: 2
From: Ohio
Oh, and I have to say this. Please Do not get confused when you swapped the best tires, and air filter, and your ECU displays the same or 2-3+ MPG that you always have had.
The thing that the ECU can realize = Engine Load + Engine Air + Throttle Position + Vehicle speed. These had been pre-programed and calculated to display you an ESTIMATED mpg on your display. It is no way to Measures the Tires fraction factor
By swapping those 2 things, you may only be able to see 2-3 MPG increase, or nothing at all (the ECU may recognize the air filter, but may not be enough.) These 2 things will only affect you by Actual Driving, not displayed MPG.
The thing that the ECU can realize = Engine Load + Engine Air + Throttle Position + Vehicle speed. These had been pre-programed and calculated to display you an ESTIMATED mpg on your display. It is no way to Measures the Tires fraction factor
By swapping those 2 things, you may only be able to see 2-3 MPG increase, or nothing at all (the ECU may recognize the air filter, but may not be enough.) These 2 things will only affect you by Actual Driving, not displayed MPG.
Pole Position
Joined: May 2009
Posts: 2,838
Likes: 26
From: GA
Andy, try and make sense for me with the fact that if the hybrid engine can be rated ICE only at 245hp, the FWD with electric motor kicks in only 20 more and you still get to 295 total hp. Something's not right there. The hybrid version doesn't/can't gain 45hp from the electric motor alone. Can you provide a link to that quote?
Mine was built late in July 09 I like to think I got the very last RX sunglass holder I'll sell it separately to anyone for $10,000, just send me a PM.
Yea, I see your chart. That's the problem now with Lexus/Toyota. They stopped publishing the power output of the engine separately, only total power for hybrids. Marketing people got involved with this, they only want casual buyers to know that the hybrid has more total HP than their non-hybrid twin. They don't want to confuse people with a separately published engine HP rating that is less. You can't infer from the chart that the 270HP 2GR-FE RX350 engine is going to have the same output as the 2GR-FXE in the 450, because while related, it is a different engine.
ADD: I think I've gotten a bit obsessed with finding some actual Lexus numbers to compare just to see exactly what is different, so I continued hunting. These are the specific differences between the 350 and 450 engine only specifications for the 2013 model from Lexus pressroom website.
Engine Code: 2GR-FE vs 2GR-FXE
Horsepower: 270HP @ 6,200rpm vs 245HP @ 6,000rpm
Torque: 248 lb-ft@ 4,700rpm vs 234 lb-ft @ 4,800rpm
Compression Ratio: 10.8:1 vs 12.5: 1
Redline: 6,400 rpm vs 6,200 rpm
The 350 numbers are based on 87 octaine, the 450 numbers are based on 91 octane.
I like to think I got the very last RX sunglass holder I'll sell it separately to anyone for $10,000, just send me a PM. Yea, I see your chart. That's the problem now with Lexus/Toyota. They stopped publishing the power output of the engine separately, only total power for hybrids. Marketing people got involved with this, they only want casual buyers to know that the hybrid has more total HP than their non-hybrid twin. They don't want to confuse people with a separately published engine HP rating that is less. You can't infer from the chart that the 270HP 2GR-FE RX350 engine is going to have the same output as the 2GR-FXE in the 450, because while related, it is a different engine.
ADD: I think I've gotten a bit obsessed with finding some actual Lexus numbers to compare just to see exactly what is different, so I continued hunting. These are the specific differences between the 350 and 450 engine only specifications for the 2013 model from Lexus pressroom website.
Engine Code: 2GR-FE vs 2GR-FXE
Horsepower: 270HP @ 6,200rpm vs 245HP @ 6,000rpm
Torque: 248 lb-ft@ 4,700rpm vs 234 lb-ft @ 4,800rpm
Compression Ratio: 10.8:1 vs 12.5: 1
Redline: 6,400 rpm vs 6,200 rpm
The 350 numbers are based on 87 octaine, the 450 numbers are based on 91 octane.
Lexus Champion
Joined: Feb 2004
Posts: 1,973
Likes: 55
From: Ohio
Official Lexus specs:
RX350
RX450h
2010 RX350
P.S.
One of front electric motors (MG2, permanently attached to front wheels) is 155hp.
There's only one rear electric motor, which is 67hp.
Battery pack can only supply 27hp; the rest is supplemented by MG1, which is why the hybrid numbers are not straight-forward, as the power curve includes 2 (3 in AWD) electric motors and a gas engine.
RX350
RX450h
2010 RX350
P.S.
One of front electric motors (MG2, permanently attached to front wheels) is 155hp.
There's only one rear electric motor, which is 67hp.
Battery pack can only supply 27hp; the rest is supplemented by MG1, which is why the hybrid numbers are not straight-forward, as the power curve includes 2 (3 in AWD) electric motors and a gas engine.
Last edited by vlad_a; Apr 9, 2013 at 12:48 PM.
Pole Position
Joined: May 2009
Posts: 2,838
Likes: 26
From: GA
Ok, I came up with the same article for the 2010 model and although I can't argue what's there, the math for the engine and electric motor do not add to the 295 total hp. In previous Lexus pages, the engine was listed as 275hp and the electric power was 20hp for the total of 295hp.
Official Lexus specs:
RX350
RX450h
2010 RX350
P.S.
One of front electric motors (MG2, permanently attached to front wheels) is 155hp.
There's only one rear electric motor, which is 67hp.
Battery pack can only supply 27hp; the rest is supplemented by MG1, which is why the hybrid numbers are not straight-forward, as the power curve includes 2 (3 in AWD) electric motors and a gas engine.
RX350
RX450h
2010 RX350
P.S.
One of front electric motors (MG2, permanently attached to front wheels) is 155hp.
There's only one rear electric motor, which is 67hp.
Battery pack can only supply 27hp; the rest is supplemented by MG1, which is why the hybrid numbers are not straight-forward, as the power curve includes 2 (3 in AWD) electric motors and a gas engine.
Pole Position
Joined: Mar 2013
Posts: 249
Likes: 0
From: NJ
My '12 RX can get 27 mpg's highway around 70mph with cruise control. When I drive in Philly it drops to 15 mpg.
It is definitely driving habits. I never jack rabbit from a stop light,and I coast to a red light.
In my suburbs I average around 21-23 mpg's.
It is definitely driving habits. I never jack rabbit from a stop light,and I coast to a red light.
In my suburbs I average around 21-23 mpg's.