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Hi all,

I have Hankook Kinergy GT tires installed from the factory. I believe the driver's side sticker says the tire pressure for the car should be around ~35 PSI. Do energy efficient tires need more tire pressure for less roll resistance?

I will probably get rid of these tires after they wear out. I'm not sure there is a significant benefit of gaining 1-2 mpg vs better control in inclement weather. If anyone has a 2nd opinion with this, please share your thoughts. This is the first time I've driven with energy efficient tires.

Thanks
 

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The door sticker is the recommendation by Toyota for the best blend of fuel economy, safe handling, and ride comfort. I tend to run 3 lbs over headed into winter partially for the sake of slightly improved fuel economy, but the real reason is to give me just a bit of cushion for temperature impacted pressure changes that trigger the low tire light

Whatever pressure you intend to run make sure you are checking and adjusting a "cold" tire. That means first thing in the morning before the car has been driven for the day or has at least sat for a couple of hours. Even driving a mile to a gas station will often add a lb or 2 over what it was sitting in the garage or driveway. Sunshine is also an issue as is later in the day if you have the typical day where the low to high varies by 20 degrees and even more so in the desert where that range can be 50 degrees. Obviously that doesn't mean not addressing a low tire if it happens to occur at 3 pm. This is just in the matter of setting the pressure you want to run at.
 
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You want low rolling resistance tires for best fuel economy.
Tire pressure recommended is not just for fuel economy. it is also for average comfort, stability and safety. Normally, tire pressure is recommended per vehicle load.
You WILL see recommendations from the Overinflators Club, that run their tires at very high pressure claiming some amazing mpg gains. Don't forget that if you go that route, you:
1. lose friction with road
2. over strain suspension elements and body with much stiffer ride
3. eat tires on the center line
4. interfere with steering geometry/vehicle stability, designed for certain tire behavior on the road
5. place more strain on your spine and kidneys with harsher ride.

Do you feel lucky?

Instead, maybe work on hypermiling driving habits development. That for sure will give you decent mpg gain.
 

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You want low rolling resistance tires for best fuel economy.
Tire pressure recommended is not just for fuel economy. it is also for average comfort, stability and safety. Normally, tire pressure is recommended per vehicle load.
You WILL see recommendations from the Overinflators Club, that run their tires at very high pressure claiming some amazing mpg gains. Don't forget that if you go that route, you:
1. lose friction with road
2. over strain suspension elements and body with much stiffer ride
3. eat tires on the center line
4. interfere with steering geometry/vehicle stability, designed for certain tire behavior on the road
5. place more strain on your spine and kidneys with harsher ride.

Do you feel lucky?

Instead, maybe work on hypermiling driving habits development. That for sure will give you decent mpg gain.
All good stuff! For sure easy driving habits contribute far more to good fuel economy and reduced wear and tear on the car than special tires are tweaking tire pressure.
 
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I run 43lbs in the front and 35lbs in the back. (215/55r17 V rated) I look at my tires every day (that I use the car), for shoulder wear and center tread wear. (Michelin Premier A/S) Center tread wear is also caused by higher speed....like 70-80mph +. (70mph is legal in many states out away from large population centers)(and don't even think that people don't overshoot that by 10 to 20%....+) The wider the tire, the more centrifugal force applied to the center of the tire.... Running 275/60r15 BFG radials rear and I believe 215/70r15 front on a 69 Chevelle, had center and shoulder wear...trying to keep up with the traction thing with 28 to 30lbs air(rear)....yet still had center wear....hmmm.

Anyhow, everyone has an opinion....mine was shaped in a tire store as my first job, and for decades as an independent mechanic (as opposed to a dealership). My goal is better mileage (higher pressure) wife is pleased with the ride and comfort, and I don't go around corners on 2 wheels and very rarely go over 65mph. I look at it as: If the tire and the car were matched....with the correct pressure specified, then there would not be center or shoulder wear. But....since life does not only occur in a laboratory (controlled conditions)….one needs to make adjustments for local terrain and seasonal conditions....apparently one size does not fit all. Speed ratings (V H T >) also affect sidewall stiffness.

So if these engineers were so high and mighty that they didn't make wrong determinations on specifications, and dream up things like putting the front brake rotor inboard of the wheel hub (on certain years/models of Hondas)(or your manufacturer of the day, with_________fill in the blank) then mechanics would be like the "Maytag repairman" sweeping the shop until a job came in?

This works for me....just as a Doctor prescribes certain medicines (for certain ailments) that can exceed the normal limits (for a certain amount of time)...this is the "prescription" for my vehicle. My next tires are Hankook Kinergy PT 225/55R17 97H.

As a charter member of the Overinflators Club I have been lately running 50mpg as per the cars computer (lowest was 44.9 last Winter) with an occasional 55.1 and 53.1 reading on a particular 35 mile (one way) segment. It does not seem like such an achievement when gas is $1.38....but it is like golf, in that I am competing against myself.

Other people are more than welcome to run whatever tire pressure makes them happy, for whatever reason, medical or otherwise. There is always room for a second/third opinion.
YMMV Your Mileage May Vary
 

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If I wrote a reply it would be almost identical to this one ^^^^^^^^^^^, over 100k miles with higher inflation pressures and driving since 1966. Wife likes hers at factory specs so we just live with separate opinions. Averaged 53 + MPG with my Mirage rated at 42 highway and 47 with my Echo rated close to the same. NO change in wear characteristics and longer tire life due to less heat generated and driven in conditions such as glare ice. Higher pressure smaller contact patch with higher load on the patch.

Drove my Mirage 30k miles on $1k in fuel, got 53 MPG driving it home when purchased new. The Echo is currently at 3.2 cents a mile with fuel here at $1.499. 1500 miles a month for $50, not as much now with the current virus situation. Wife used a quarter tank in her vehicle, in the last month, since we mostly go in mine.
 

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My Camry Hybrid XLE came with Hankook Kinergy GT tires as well. They are 235/45 18”.

I don’t like them. They are slippery when wet, are somewhat noisy, and have quite a bit of impact harshness. I find my Camry’s ride to firm for my tastes. I’m not sure if that’s because of the big wheels or non-comfort tires. I run mine at 34 PSI and check them weekly with a high quality gauge. Adding a pound or two of air with a bicycle pump is super easy and convenient. I average a lifetime 45.0 mpg (manually calculated). The trip computer reads 44.5. I have gotten as high as 52.0 on a full tank. Keep in mind that the XLE gets the worst mileage of the hybrids.

I have only 12,000 miles but am thinking of changing to something more comfortable — and perhaps to a 17” wheel.

My Subaru Crosstrek with 18” wheels has 225/55 tires and rides great — even better than luxury vehicles. Big impacts almost never make their way into the cabin. After changing out its tires at 10,000 miles the ride, impact harshness, and noise all improved. But it still rode great on the OEM tires.

By impact harshness I mean impacts varying from tar strips, to bots dots, broken pavement and pot holes.
 

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My Camry Hybrid XLE came with Hankook Kinergy GT tires as well. They are 235/45 18”.

I don’t like them. They are slippery when wet, are somewhat noisy, and have quite a bit of impact harshness. I find my Camry’s ride to firm for my tastes. I’m not sure if that’s because of the big wheels or non-comfort tires. I run mine at 34 PSI and check them weekly with a high quality gauge. Adding a pound or two of air with a bicycle pump is super easy and convenient. I average a lifetime 45.0 mpg (manually calculated). The trip computer reads 44.5. I have gotten as high as 52.0 on a full tank. Keep in mind that the XLE gets the worst mileage of the hybrids.

I have only 12,000 miles but am thinking of changing to something more comfortable — and perhaps to a 17” wheel.

My Subaru Crosstrek with 18” wheels has 225/55 tires and rides great — even better than luxury vehicles. Big impacts almost never make their way into the cabin. After changing out its tires at 10,000 miles the ride, impact harshness, and noise all improved. But it still rode great on the OEM tires.

By impact harshness I mean impacts varying from tar strips, to bots dots, broken pavement and pot holes.
I'm also thinking of switching to 17" rims and appropriately large tires to bring the overall diameter back to normal. The car (2018 XLE hybrid) loses traction when braking in the dry on a downslope and you go over a spot where the top 2" of the road surface is gone (and I'm not a leadfoot by any means).

It also feels dangerous when braking (again lightly) on a wet road when you go over a metal plate (what we used to call manhole covers).

In either case, since it's usually just one wheel that loses traction at any given time, the rear end usually bounces sideways a bit). This is by far the worst car I have driven for this particular situation, and I'm convinced it's the cool-looking rubber-band tires that are in vogue right now. If I wanted a racer I wouldn't have bought a Camry:D

Side-note - I have been considering a 2020 Highlander hybrid, and want the birds-eye, but that comes with the rubber-band tires, so I'm having a hard time deciding which is the lesser of two evils.
 

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I'm also thinking of switching to 17" rims and appropriately large tires to bring the overall diameter back to normal. The car (2018 XLE hybrid) loses traction when braking in the dry on a downslope.....
In either case, since it's usually just one wheel that loses traction at any given time, the rear end usually bounces sideways a bit). This is by far the worst car I have driven for this particular situation, and I'm convinced it's the cool-looking rubber-band tires that are in vogue right now. If I wanted a racer I wouldn't have bought a Camry:D
30" rims (on other kinds of cars) look cool (I suppose) with a thin band of rubber....why not just put a solid tire on it like a fork lift?
Anyhow, things go in and out of style....but you know, people with those kind of wheels don't talk much about hitting a pot hole and bending that $500 rim....just like people don't talk about the trip to the casino that cost a grand...or so.
Polyester pants are never coming back, mullets maybe in 20 - 30 more years, mini skirts...soon I hope. In each era it is hard to believe that our favorite thing will be "dated".....but the more gray hair and age one accumulates, sometimes.....comfort overcomes looks.....I know, I know.....I'm just say'in….one day it could happen to you also....🕰
 

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I got the Kinergy's on Pop's 98 Sienna, then he gave me the van. 215-70-15, they are great and cost $400 for everything. I think the 45 aspect ratio is the problem causing the harsh ride qualities. Those on my van are rated 680 treadwear, traction A, temperature A. Those tires are not going anywhere.
 
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