Tire Upgrade

I picked up my 2006 two weeks ago and drove 2 miles to the Goodyear dealer and had Comfort Treads installed at 40/38 psi
I still have my 2004 with 87k miles total, 47k with Bridgestone RE950.

I've driven both for almost 3 weeks and here's my observations.
My 2004 is ten times more stable on the freeway (34/33 psi).
My 2006 rides MUCH softer and quiter.
My 2004 is getting 51mpg and my 2006 is at 49mpg (I drive about 900 miles per week).
My 2004 has about 0.220" tread depth left (center of tires, driver side)

 

<div class='quotetop'>QUOTE(nyprius @ Jun 26 2006, 11:46 AM) [snapback]276822[/snapback]</div>

NYPRIUS...thanks for the research. I am new to the Prius world, specifically this forum. Is there a way to save posts like this somehow...I see a favorites list but not sure if that is used for bookmarking favorite posts, and if so, How to do it. Thanks for your help..

 

y'all!

I just wanted to chime in and report that I put TripleTreds on my 2005 last Friday. I ended up going with the 195/65R15. I was a little confused when the GPS clearly showed the 2% difference in distance travelled, yet the speed seemed to be right on the money. After reading through this thread, I now know why!

Anyway, they seem to be much quieter for me. I drive mainly on two-lane black top that gets a load of gravel and oil spread on it every few years, so it's not the smoothest surface. The TTs definitely reduce the amount of noise form this type of road. Also, the tires seem to grab the road so well that the steering now seems unusually sensitive. I guess the Integrities were sliding around more than I thought. Anyway, the new road feel sometimes tends to give me a bit of motion sickness, but I'm sure I'll get used to it.

The one thing that I've finally realized about the way the TTs feel is that they're HEAVY! They each weigh seven pounds more than the Integrities, and I'm coming to the conclusion that I can feel that difference (I may still be imagining it, though).

So far, the MFD mileage has dropped from 53 to 47, but that doesn't account for the 2% distance difference. I'll have to factor that into my spreadsheet from here on.

I'm happy enough at this point although I was wondering if there's a way to recalibrate the odometer? I looked in the various "hidden" diagnostic screens hoping to find a Revs per Mile entry, but no luck. Also, I noticed that the navigation was drifting off, so I tried the "tire change" calibration. Just what does that do? The manual doesn't really go into much detail about what it does or how to properly use it.

Now all I have to do is convince my wife that she should upgrade the tires on her Prius!

 

i drive an '04, 55,000miles. went to discount tires here in san diego at 47K and bought the Falkens, hated them, they felt squirllier (is that a word?) then the OEMs and noisier and i traded them in for the comforttreds, which were still not what i was hoping for, tho better. they felt ok but the car still wandered and i took a 5 mpg hit. i traded them for the tripletreds, promising the mgr at the tire store not to show my face again, and i am mostly satisfied, better straight line tracking, only a 2-3 mpg hit, excellent traction and the tread looks right pretty when i see it as i walk up to the car.
would i recommend the TTs? sure, it's clearly a safe and high quality tire. tho, still, not perfect. i hate losing the 2-3 miles per gallon. i run at 42-40, noise is less than OEMs, which never bothered me anyway, and 80K sounds like a really good deal, re cost.

 

<div class='quotetop'>QUOTE(artie @ Jul 30 2006, 08:48 PM) [snapback]294799[/snapback]</div>

Do you mean that

• the car was too sensitive to steering input?
• the car followed ruts on the highway or other road irregularities?
• the car didn't respond to steering input?
• the car was too sensitive to sidewinds?
• the ride was too bumpy?
• something else?

 

I put Michelin MXV4+ LRR tires on the Prius. Before, with worn Integrity tires, we were getting 55 miles per gallon on average. The first tank after the tire change was 47 mpg, the second one 48 mpg, and this one looks like it could be very close to 50 mpg. Note that I have been carrying passengers more often in the past 3 tanks (which is probably responsible for a 1-2 mpg difference).

I can attribute a 1 mpg loss due to the increased diameter of the Michelin tires. The Michelin tires complete 849 revolutions per mile whereas new Integrity tires rotate 855 times per mile. Worn integrities (down to the wear bars) lose about 1/4" of diameter, a 1% difference. That means worn Goodyear Integrity tires in the stock size rotate 863.8 times per mile. That is almost a 2% difference in distance traveled per revolution compared to my new Michelin MXV4's in 185/65R15.

Analyzing these different aspects of my latest mileage figures, I now believe that the tire break-in period is longer than 1,000 miles. There are about 1,400 miles on the tires so far. I believe I will return to getting very close to my old mileage figures within the next 500 miles. The MXV4+ tires are LRR and the same weight as the OEM tires. They certainly provide a lot more traction than the OEM tires, but I am even more impressed with how much they have muted road noise. Not only are they quieter, they soak up bumps a lot more effectively while providing much better steering response. I thought these attributes were mutually exclusive until now. Perhaps the Michelin is just a much better design. I highly recommend these tires. They were a great deal at about $340 installed since Costco was offering a $60 rebate on selected Michelin and BFG tires.

For those that might ask, I run pressures of 40/38 psi. 42/40 is a lot more jarring, and 38/36 causes too much center wear (too bad I didn't know this until it was too late for my Goodyear tires).

 

The tires were the first thing I noticed when I picked up my new 06 a couple of weeks ago...they looked so "thin" and small...

My old 91 Camry has Blizzaks on year round...hills, snow in winter...I live on a steep hill.

Then on my way home from service with only 20 miles on the car, I pull over to the side to make a call and BOOM, right rear tire blows out.

Toyota was nice enough to send someone since couldn't get their roadside on cell....went back to shop. 4 inch slash...completely through tire....replaced it...got an extra, but think I will be replacing the Itegrities much sooner than needed, although my mechanic says they are good tires.

Will see this winter. My driveway takes me up a steep hill and even when plowed, the slip sends cars into ditches.

We'll see. Printed out some of these posts and will consider the TTs and the Falken Ziex Ze 512....

terri

 

Terri,
Anyone who likes Integrities should have their head examined IMHO.

Recovered gas guz,
I put Comfortreads on my new 06 and at 2500-3000 miles saw a 3mpg increase. This is not driver related (I just put 86k on my 04 Prius).

 

I am wondering what is wrong with my car's handling now.

When I first got it there was no problem driving on the freeway. I switched to 1" wider aftermarket rims (lighter than the OEM's, 13.8lbs) and went with a 205/60/15 tire, the Falken Ziex 512...someone else stated they used that tire and was very happy with the results.

Not too soon after switching, I started to notice a very squirrelly feeling in driving at freeway speeds. The steering response seemed to be hit-or-miss. Also, it seemed hard to hold a straight line. Sometimes it would feel like the road would grab the car.

This coincidentally started to happen at the same time the steering issue recall came out. Well, I thought that that had to be the problem, not the new tires and rims. I switched back to the OEMs before having the recall work done and sure enough, that drifty feeling on the freeway was there.

Now for the mystery, after getting the steering fix done and driving away from the dealer everything felt fine, freeway and all. I immediately switched back to the Falkens...and the poor freeway handling is back! What gives?!

I'm starting to think that it is a problem with the caster being just slightly too negative with these 205/60/15 tires which have an ever so slightly taller sidewall and overall diameter.
Has anyone out there experienced something similar to this or dealt with caster adjustments?
This has been frustrating the heck out of me. :angry:

 

Just thought I might add that I saw about a 4-7mpg drop with the new tires and rims. Plus, accelleration felt a bit more sluggish.

The OEM tire/rim combo weighed 31lbs. Tire approx. 16.8lbs, rim 14.2lbs.
The new tire/rim combo weighed 34lbs. Tire approx. 20.2lbs, rim 13.8lbs.

I wish I had gone with a 195/65/15 size tire and looked at a lighter one as well. There are several choices for 18lb tires in a 195/65/15 but I don't recall seeing any 205/60/15 size tires below 20lbs.

 

<div class='quotetop'>QUOTE(slortz @ Aug 4 2006, 06:33 PM) [snapback]297926[/snapback]</div>

It sounds like you're describing what many tire experts call tramlining. The TireRack has an excellent little article on the problem, causes, and solutions here.

This is a relatively common problem with very low profile performance tires. I'm surprised that you encountered this with your modest choice of tires, but it's common with performance tire upgrades to economy cars. They will tend to follow the very shallow ruts, grooves, or depressions on roads. The problem is very bothersome, especially at highway speed on old rutted roads or newer grooved concrete expressways. I never experienced this with the 195/65-14 Falkens on our Civic, but since you are, you might see if the shop that sold you the tires can let you swap the Falkens for something else. Some tire dealers will credit you the cost of the tires that didn't satisfy you it you return them within 30 days. My taller 195/65HR15 Continental ContiProContact tires haven't exhibited this behavior on our Prius, so the 1-2% increase in tire diameter is probably not the cause.

I suspect the problem may be related to an offset change with the change in wheels and would re-verify the difference in the offsets of the wheels before worrying about alignment or anything else. Ever the skeptic, I wouldn't ask if the new wheels had the right offset. The right answer is too obvious and easier to give than the correct answer. I would ask the shop that sold you the wheels for the offset measurement of the new wheels and ask a Toyota dealer for the offset of the OEM wheels or measure it yourself.

 

I got tired of searching for 16" tires. I just purchased 17" Enkei 5+ wheels and BFGoodrich g-Force Sport 205/45/17 tires for our 2004 Prius. Total weight about 38 lbs.

So this...
[attachmentid=4429]

Is now this...
[attachmentid=4430]

I expected a pretty rough ride, but that isn't the case at all, even running 38/40 in the tires. It rides great, is quiet, tracks like it should (doesn't wander on the highway) and goes where I point it. We'll be driving them 700+ miles in the next week. I'll see how the mileage turns out. At this point, I'd gladly give up a few mpg to get a car that behaves itself and feels safer.

 

Based on the recommendations and discussion here, I just put a set of 195/60/15 Comforttreds on my '05. I've driven about 100 miles on them and have not experienced a loss of MPG. I inflated them to 40/38. About 90% of those miles are highway and even in 100 degree heat, my MFD is reporting around 52mpg, which was pretty typical on my well worn Integrities.

They are definitely quieter. The ride seems about the same, possibly a little bit smoother, but not significantly. Handling has definitely improved. I keep having to correct for over-steering because it's cornering so much tighter.

I can't wait to try them out in the rain.

 

For those who bought Tires AND Wheels for Winter use...

Where did you find the best deal, what deal did you get and what type of tires and wheels did you purchase? I see the Blizzaks are mentioned above. REVO 1 or WS50???

I'm just planning ahead here as our Prius is expected (we hope) by Oct 15. My wife needs to drive about 13 miles each way to work on roads that can be nasty without extra traction in Winter.

Thanks,
Mike

 

<div class='quotetop'>QUOTE(mongo @ Aug 9 2006, 09:16 AM) [snapback]300226[/snapback]</div>

Sweet Ride!
So how much was the total damage?
And how much did you spend for installation?
Any trouble fitting the sensors to the new wheels?

 

Interesting posts. My Prius came standard with Bridgestone Turanza ER30 195/55/R16 87V tires.

Handling is good and I don't notice anything amiss on highways with the steering, except that is feels too light.