Lexus CT200h Forums banner

1 - 18 of 18 Posts

·
Registered
Joined
·
205 Posts
Discussion Starter #1
I see in one of the other threads we are now talking about Tire Pressure.

Thought it be best to start it's own,so here we go.


I just set mine at 36 front,35 rear. I do feel a difference.I might try 38-37 next.

How high do you feel one can go before we see diminished returns?
 

·
Registered
Joined
·
7 Posts
what do you mean by "diminished returns" biglefty?? Does anyone know what Lexus suggests??....someone told me it should be in the owner's manual. The tires say max is 51....I have all four of mine at 45.
 

·
Registered
Joined
·
414 Posts
what do you mean by "diminished returns" biglefty?? Does anyone know what Lexus suggests??....someone told me it should be in the owner's manual. The tires say max is 51....I have all four of mine at 45.
The recommended "cold" tire pressures are always on the drivers door jam. Follow them for optimum performance and wear.

Read the following article for important information on maintaining proper pressures:
http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=1
 

·
Registered
Joined
·
205 Posts
Discussion Starter #5

·
Registered
Joined
·
205 Posts
Discussion Starter #6
what do you mean by "diminished returns" biglefty?? Does anyone know what Lexus suggests??....someone told me it should be in the owner's manual. The tires say max is 51....I have all four of mine at 45.
There is a point when we don't see an increase of MPG and the ride becomes very harsh. That would be diminished IMHO.
From the stock 33-32 to 36-35 ,I can feel a ride difference and feel the car rolls better.

How far can one add air before ride quality suffers? Guess that is up to each individual .
 

·
Premium Member
Joined
·
661 Posts
Mythbusters did an episode on this. Higher the pressure the less tread with surface contact thus lower resistance and better MPG. They tested at 15% higher than recommended vehicle pressure on door. And in the end only got a savings of $70 a year in gas. Any higher and you run risk of blow out and harsh rides so is that really worth $70 a year. Lower pressures had more tread surface contact and higher resistance thus lower MPG but not by much.
 

·
Registered
Joined
·
180 Posts
My dealer set the pressure to 36 psi on all tires. Another problem with over inflation is uneven tread wear! So, are you willing to trade shorter tire life for mpg? :rolleyes:
 

·
Registered
Joined
·
130 Posts
Mythbusters did an episode on this. Higher the pressure the less tread with surface contact thus lower resistance and better MPG. They tested at 15% higher than recommended vehicle pressure on door. And in the end only got a savings of $70 a year in gas. Any higher and you run risk of blow out and harsh rides so is that really worth $70 a year. Lower pressures had more tread surface contact and higher resistance thus lower MPG but not by much.
Mythbusters was over-inflating the tires above the manufacturers recommended maximum tire pressure. The Michelin OEM tires have a recommended max of 51psi. As long as you're with in manufacturer spece, you aren't risking a blowout.

Based on my previous experience with my Civic Hybrid, where I found that my mileage increased by nearly 1 mpg per additional psi, I think that Mythbusters should have done their test with different cars. I believe that they would have found that mileage is increased by a percentage and that higher mpg cars would have more of an mpg increase than lower mpg cars do.
 

·
Registered
Joined
·
391 Posts
Mythbusters was over-inflating the tires above the manufacturers recommended maximum tire pressure. The Michelin OEM tires have a recommended max of 51psi. As long as you're with in manufacturer spece, you aren't risking a blowout.

Based on my previous experience with my Civic Hybrid, where I found that my mileage increased by nearly 1 mpg per additional psi, I think that Mythbusters should have done their test with different cars. I believe that they would have found that mileage is increased by a percentage and that higher mpg cars would have more of an mpg increase than lower mpg cars do.
I pumped mine up last night before a 50 mile drive on a fresh tank of gas and reset of the MPG meter. Have to say it did seem like a good bump up in MPG at 48. First 4 tanks came out 44,46,45,40 (Indicated).. Hope the final result is also up... :)

Since we all seem to get slightly less actual MPG than is indicated on the meter.... I'm hoping we can all use (indicated) and (actual) or (ind)/(act) when listing MPG numbers. My actual numbers have been about 2.3 mpg lower on average...
 

·
Premium Member
Joined
·
957 Posts
I run mine @ 40 PSI for all 4 tires.
 

·
Registered
Joined
·
89 Posts
Mine came from the dealer set at 35 psi all around. I haven't changed them.
 

·
Registered
Joined
·
169 Posts
Another problem with over inflation is uneven tread wear!
That is a myth, unless you over inflate by more than 30%. The influence of centrifugal forces on wear is much greater than that of tyre pressure.

Over the last fifteen years, I have routinely over inflated my tyres with 20%. It brought me noticeably improved economy and handling, a slightly less comfortable ride and no uneven tread wear whatsoever.
 

·
Premium Member
Joined
·
1,101 Posts
Hmmm, I think I'll try raising my tire pressure and see how I like it and how many MPG's I can gain. Hard to believe I can get even BETTER mileage with this car!
 

·
Registered
Joined
·
48 Posts
Higher pressures = harsher ride = more likelihood of shaking something loose so rattles start. Once started, hard to find and to stop.

Not worth it in my book. I prize the silence more than anything else.

And I'm getting mpg's in the low- to mid-50s (per both ScanGauge and built-in AVG reading) at the recommended 33/32, even in Power mode, with a bit of care.
 

·
Premium Member
Joined
·
1,101 Posts
danrichman - I raised mine up from the recommended pressures to 38 psi and you're absolutely right, it is harsher and I agree about the higher potential for rattles part. I'm going to lower them back this weekend.
 

·
Registered
Joined
·
11 Posts
I'm going to increase the pressure from the Lexus recommened to 35/34.. Do I need to reset the tire pressure monitor when I do this?
 

·
Registered
Joined
·
130 Posts
I'm going to increase the pressure from the Lexus recommened to 35/34.. Do I need to reset the tire pressure monitor when I do this?
Once you decide on the final pressure, you should reset the monitor. Otherwise, you won't know until the pressure drops below the factory pre-set pressure, rather than when it intially starts dropping.
 
1 - 18 of 18 Posts
Top