Has anyone tried out a set of Hankook Optimo H727's on their OEM 15" rims?

I purchased my 2010 Prius IV on 4 September and traded out my OEM Yokohama tires for Hankook Optimo H727. The ride has been very smooth and quiet. Over the course of three fill-ups my fuel economy has ranged from 50 to 51 mpg with my driving consisting of roughly 70% city vs. 30% highway. Overall I am very pleased and am curious to see how they will handle the snow in a few months.

Coincidentally my four like-new Yokohama tires are available for purchase at a deep discount. If you are in the Chicago area, please check out my posting in the For Sale folder.

Happy motoring!

 

I just got the Hankook Optimo H727's installed on my 2008 Prius. The original tires had 41K miles on them and I was afraid to try and get through another Kansas winter with them. My overall average MPG on the originals was about 46 with probably a 60/40 blend of highway/city driving. So far the Hankooks handle much better, have much better grip, seem to do well on wet roads and my mileage so far seems barely affected, although we are in that weather transition period where it changes anyway. My average MPG for the week I've had them is 45-46MPG. I'm feeling pretty secure that they will be a much better choice for snow driving.

 

You will find this thread interesting:

http://priuschat.com/forums/gen-ii-...0-how-your-hankook-h727-tires-holding-up.html

 

My tire dealer says that the Optima H727 are not available in a size that will fit the 2005 Prius. How are you finding the Hankook H727 that will fit this car?

Chucka

 

What size tire are you looking for?
Here is a link to the Hankook site:
Welcome to Hankook Tire International Website
The Optimo 727 is listed under Passenger Car, Standard

Meanwhile, here is a list of sizes -
P185/65R14
P185/60R15
P195/60R15
P215/60R15
P195/65R15
P205/65R15
P205/70R15
P215/70R15
P235/75R15 XL
P205/55R16
P205/60R16
P215/60R16
P225/60R16
P235/60R16
P205/65R16
P215/65R16
P225/65R16
P235/65R16
P225/55R17
P215/60R17
P225/60R17
P215/65R17
P225/50R18
P215/55R18
P225/55R18

You might want to order through Tirerack.com.

 

In July 2011 I put 4 Hankook H727 on the OEM wheels for my 2005 Prius at just over 72,000 miles.
The new Hankooks are size P195/60R-15, same size as the Michelin Hydroedge tires which I had put on the OEM wheels just a few days after I purchased the car in 2005.
The Hydroedge tires have been excellent, and in fact had an 80,000 mile warranty, but they now had sidewall cracking, which is to be expected on tires after 5 or 6 years.
The car handles just fine, and the ride is noticeably quieter than the Michelins, but that is probably normal for brand new tires. I think my mileage is reduced a bit, now. Of course it is summer, so I cannot report how they will do in rain or snow (the Hydroedge was great in the rain.)

 

I put on a set of 195/60/R15 Hankook Optimo H727s on my 2009 prius at 40K miles, and I've got about a thousand miles on them. I bought them because of the many good reviews and ratings I have seen. Sometimes I wonder if manufacturers have teams of people that write these good reviews. I usually start with the bad reviews, but I ignored them for the Hankooks because there were so many good reviews, I liked the price and I needed a tire with good traction in the snow. I should have placed more weight on the bad reviews.

Here's my experience with them:
Traction: I have not driven them in the snow, but I have in heavy rain several times. No hydroplaning experienced at highway speeds (+) in very heavy rain.

Pick up: they are a bit smaller in diameter, so you have a little bit more (noticeable) get up and go.

MPG: was getting 52.2 MPG with my Integrities. With the H727s, the mpg dropped to 51.2 MPG, but that coincided with a drop in outside temperature also, so I am guessing the tires had no effect on mpg.

Air pressure: started with 42 lbs in front, 40 in rear. Today (warm day), a month later, they are at 40 front, 39 rear. Maybe a little leaked out before they got seated, or the tires stretched a bit.

Noise: They are very quiet as compared to my OEM Integrities. It took a while before they got quiet. Probably needed to get broken in.

Handling: This is where I am extremely disappointed. These tires are dangerously unstable at high speeds and just mushy at low speeds. It's almost like you're driving a boat. When you turn the steering wheel, it takes a while for the car to respond. It is as if the sidewalls are made of jelly. While the tires hold very well in sharp turns on on-ramps, once you're on the highway, if you have to maneuver quickly the car will be unstable and will not respond well to the steering.

With my original Integrities, I installed a both tunnel brace and tower brace. The handling of the car improved significantly after the brace installations. Once I installed the Hankook Optimo H727 tires, it was as if there were no braces installed at all. I would hate to see what it would be like if I didn't have the braces. It would be scary.

I did have my alignment checked, and while the alignment is on the edge of tolerances, I had no problems with the OEM tires I was driving on the day before the Hankooks were installed.

Because of the handling issues I have experienced, if I had it to do again, I would look at other tires. I am seriously considering replacing the Hankooks.

 

That is terrible news, Neoprius.

Have you tried increasing tire pressure just to see how they respond? I had the same complaint about my dB Super E-Specs when they were under 40psi. I have them at 50 psi now and they are very stable and solid. They felt that way once I got above indicated max pressure of 44psi.

 

Well, I'm running them at 42 front and 40 back. They are rated for 44 PSI max. I guess I could try that for a day or two just to see what happens...

 

It's worth a shot before you decide "to ditch them.

 

I have the h727's on my 2009 Prius. As I mentioned in my other post I agree they're more boring and slower to react. I have the tires and the handling isn't as fast as it used to be.

But "dangerously unstable at high speeds"? I'd say exactly the opposite, they helped straighten out the car for me and it doesn't wander on the highway as much as it did with the stock Integrities. I would say they're *more* stable on the highway.

 

Oops

 

He apparently is only looking at the 1xx/xx designation and not the tire diameter or revs per mile. Buying tires based on comparing 185/65R15 to 185/65R15 no matter the revs per mile is a bad way to do it.

The correct 15" Optimo H727 for a Gen II Prius would be a choice between 195/65R15 at 831 RPM* or 195/60R15 at 858 RPM**.

* The lower revs per mile means your spedometer/odometer will be off a bit. You can test different PSI to see if you can make it more accurate.

** Of course some on Priuschat swear that the speedometer/odometer are off with the 855 RPM of the OEM tire.

Either way you'd probably be wise to test the speedometer/odometer at different tire pressures. The rule of thumb I read is 5 PSI changes the revs per mile by about 1%.

 

That may work out. My dB Super E-Spec tires are rated 848 revs pre mile and at 52/50psi the speedometer reads between 1.5mph and 2mph faster than my GPS (GPS accuracy at time of measurement was 20ft.). When I checked them last time at 40psi I was closer to 2mph too fast. Maybe the extra air pressure caused the rolling diameter to be a bit larger and marginally slowed the speedo down?

 

Yeah, I'm assuming the rule of thumb breaks down the closer you get to or the further above sidewall max pressure. Maybe that last 10 PSI gave you .5 MPH change.

So maybe going from 35 to 40 psi affects the speedometer more than going from 40 to 50 does.

That point of diminishing returns probably also varies from tire to tire. I don't have the means to accurately test my cars or I could test varying pressures on two different brands/models of tires.

But either way it's a sad thing to think there are tire dealerships that know less about tires than I do. I didn't even know about revs per mile until I hit tirerack.com to look for tires for my Prius.

 

My guess is that you are correct. The first 10psi or so below the max inflated pressure will provide the most "growth" in tire diameter. Beyond the max PSI there will be diminishing returns. This correlates well with experimental anecdotes regarding diminishing returns on decreased rolling resistance as one goes higher in pressure beyond the max psi. 50psi is where rolling resistance is fairly maxed out in the tests I have seen.






Snapshot: effect of tire pressure on rolling resistance - MetroMPG.com

Keep in mind that the test above was constructed to test rolling resistance from a dead stop then rolling down a hill as opposed to a coast down method which is what most hypermilers do when driving.