2003/ first gen tire options???

I recently bought 4 Kumho tires:
eco Solus HM KR22

Supposed to be warranted for 100 000 miles. We'll see how long these will last. Previously had two sets of Bridgestone Potenza, which lasted around 30 000 miles.

Too early to tell - these tires came out in 2010.

Ted

 

Here's Tire Rack's test of LRR tires: When Round and Black Becomes Lean and Green

Looks like Bridgestone's Ecopia tire is available in a size appropriate for the Gen I Prius. It boasts best wet braking in the test group, FWIW.

As for plus sizing tires, I put a set of 195/60-14 tires on our 2001 Prius shortly after we got it four years ago. Handling was vastly improved, along with stability at highway speed (an oncoming semi on a two-lane road is no longer a source of dread). However, we took a pretty good mileage hit, averaging about 43 mpg now. I have a set of snows in the stock size, and mileage actually goes up in the winter.

185/60-14 tire diameter is undersized compared to stock. However, 185/55-15 is just about spot on. The downside there is that there aren't too many tire options in that size.

 

When I bought my 02 Prius used it had Michellen Harmony tires on and they seemed to preform quite well especially since I ride them at 50 psi, I replaced them with another set of Michellen Harmonys. I bought the car with 40,000 miles on it and I really cant remember the milage on the car at my replacement time but before I totalled it I was at 158,000 miles and still had the harmonys I replaced, Im thinking roughtly at 90-100 thousand miles I'll check my records and get back to you. They are about 90 dollars a tire. Now I own an 01 Prius I also bought used and they have dunlop 20's on them they seem to be working out ofk but i will probably go back to the harmonys. I hope this was helpful

 

I’m running my second set of Michelin Harmony tires on an '03. The first set lasted 80,000 miles. 38 psi is getting me 45+mpg, better than the original Bridgestones that lasted only 15K. I seriously considered a set of Nokians at one point until I found out that Bridgestone owns a chunk of Nokian and some of the Nokian tires are produced in Bridgestone plants.

 

I have Bridgestone Ecopia EP-100 (a summer tire) on both my 2004 and 2007. I am very pleased with the handling, noise level and traction. The 2004 has 18K miles on the tires and tread depth is 7/32" to 8/32". Extrapolation leads to ~50K miles of total wear, when 2/32" minimum tread depth is reached.

Ecopia is produced in sizes suitable for all three Prius generations.

 

Back in September when I got my 01, I immediately went to Discount and bought 4 new Yokohama Avid Touring S 185/65-14. They can max out at 51 psi and I run about 42psi, averaging about 46mpg. Discount matched tirerack's price and I got the certs out the door for about $360! A great tire for the Prius.

 

Any new opinions these days about tires for a 2003 Prius, with the original rims? I'm thinking of trying the Yokohama Avid Touring S, since they come in the 175/65/14 size. I'm getting tired of how quickly the Bridgestone Potenza RE92 lasts, with it's lame 160 UTCG rating (these days high performance summer tires have twice as good ratings).

Is it really a problem that the Yokohama in the 175 size has a lower load rating? It's 1019 lbs vs 1102 lbs for the Bridgestones. But the Prius only weighs 2765 lbs right?

Alternatively I guess I could go fo the Yokohama in the 185/65/14, which has a higher load rating, but I'm wondering how the larger size will impact mileage.

It sounds like people really like the Bridgestone Ecopias in general and the Michelin Energy Saver A/S, but it doesn't seem like those come in sizes that would work on the OEM 2003 rims.

Thanks for any thoughts.

 

I have the Kumho KR21 which are rated at 85,000 miles. They have been very good so far in the winter. Not sure on how long they last on the prius since they were on the car when I bought it but the tirerack has them for cheap and get good reviews are rated 6th out of 23 tires. I have had Kumho in the past and have been happy with them.
TomK

 

Thanks for in the input TomK.

I'm still wondering how much I should be concerned about the extra load (XL) tire rating that only the Bridgestone and Dunlop OEM tires for the 2003 Prius have. The XL tires are rated for 1102 lbs per tire, wheras the standard load tires are rated for 1019 lbs per tire. I thought that shouldn't matter since the curbweight of the Prius is about 3000 lbs. But I guess the issue is that the front end is heavier and so the higher load rating is needed on the front tires.

Apparently the lower load rating can be compensated for, by inflating the tires more. In this respect, the Yokohama tires seem perhaps better, because they have a higher max pressure 51 PSI vs. 44 PSI on the Kumho. On the other hand, as I say above, either tire could be purchased in 185/65/14 size (one size wider) and would then have a 1124 lbs per tire load rating. But I still remain unclear on how much, if anything, that would influence mileage.

 

You're asking all the right questions. The way the safety requirements work (the US regs, anyway), you have to do the math for the front and rear separately, and both for maximum load (use the Gross Axle Weight Ratings for front and rear), and for normal load (use the curb weight figures for the car, plus 3 imaginary 150 pound occupants seated two in front and one in back).

You can see the math gone through for the Gen 1 here. Two interesting conclusions are: (1) yes, if you're careful there's a wider selection of tires you can safely look at than the 84 XLs shown in the glove box, and (2) within that range of tires, no overinflation is actually needed for safety - you might have other reasons to prefer higher pressure, but the rated load for P175/65R14 at the factory spec 35/33 is the same for 84 XL as for 81 SL tires, so that pressure above is fine either way.

-Chap

 

Just came across this as this is what you are researching exactly. Somebody has done this for you with results!
John's Stuff - Toyota Prius Tires

TomK

 

Thanks. After I posted here, I found and read through your other posts about tires and loads. Very thorough and impressive, thanks for all the information in that thread.

For I suppose irrational reasons, I'm feeling like I'd be more comfortable with the P185 tires that have the higher load rating, although it sounds like there's no difference between between 84 XL and 81 SL tires at the normal pressue. If I'm understanding correctly, it's just that if you increase the PSI in the 84 XL then it can handle a higher load.

Mostly at this point I'm wondering what people's experiences with P185/65R14 tires are on the first gen Prius. Does the extra width effect mileage? Does the .5 inch greater diameter significantly throw off the speedometer and computer? Is P185/60R14 a better choice as far as diameter and revs per mile go?

*

Thanks TomK. I found that page myself, in my research, it was helpful, although Chap gives a much more technical and thorough explanation. Also, that page claims increasing the PSI in non-XL tires will compensate for the extra load, which in Chap's analysis is wrong. A higher PSI doesn't allow the non-XL tire to carry a higher than rated load (it's just that the non-XL 81 SL is good enough for most pratical purposes and not functionally different for loads than the 84 XL tire at the standard PSI).

In addition, that page mostly covers tires I'm not interested in or that don't exist anymore. Still wondering if anyone has tried the Yokohama Avid Touring-S on the first Gen Prius (and in what size). Sounds like some people like it on the later Prius generations.

By the way, on the Kumho KR21 which size do you have? The P185/65R14 or the P185/60R14? How's your mileage? Thanks.

 

I have the Kumho KR21 in a size 175/65R14 Bob! Since I have only had the car a month I can only tell you when the weather was in the 30's I was getting mid 40 mpg. It was a high of 2 today and I filled and was 39 mpg. That was in some of the worst traffic stop and go I have had. My commute of 33 miles was twice 2.5 hours both ways. Have actually been impressed with them as i have not had a scare yet in slippery snow roads yet. My thoughts on the tire size is that some body has engineered the best size for the car already and have always stayed with original size. If a 185/65 was to be better I would think that would have been the original size as MPG was was the main reason for this car.
TomK

 

Oh, yeah, I forgot it came in the standard size for the first gen Prius. That seems like pretty normal mileage, when you were getting in the mid 40s and good given the temperature. Sometimes these supposedly low rolling resistance tires, like the OEM Potenza RE92, don't seem to really make that much difference.

I agree with you in general about just going with what the manufacturer specifies. Although with tires there are pretty much always trade offs between handling/safety and tread wear. It also seems like the things that improve mileage tend to decrease handling/safety. So it seems legit for users to make a choice for different trade offs. I've also notice that OEM tires almost always have terrible tread wear, on any new car. Even staying in the specified size, you can usually get a tire that both performs better, wears better, and even may get better (or no worse) mileage. So I've always assumed that on OEM tires the manufaturers are just being cheap. But that's aside from the specified size.

As I said, I'm still leaning a little bit toward the 185 tires for the higher load rating, if I'm going to choose not to have the XL, even though from ChapmanF's posts, I realize this may be irrational.

Now I'm looking at the Michelin Defender. It's not the most beloved tire on the later generation Prius (where the Michelin Energy Saver A/S seems to be king of the hill). But it seems perhaps the best choice for the first gen Prius. It even comes in the 175/65R14 size, if I decided to go that way, while being slightly higher load rated than the Kumho and Yokohama (it's an 82 instead of 81 in the 175 size).

 

The last set of tires I had on my 01 were the Avid Touring S and they worked fine. I had no problems with them. I kept them at 44 front 42 rear. They did lack good wet traction when kept at those pressures (especially when wet and cold) but the climate here is sort of mundane. They got great mpg and had no uneven wear problems. They easily handled the load.

 

Is the load a problem on these cars with this small tire size? I have never even thought of that on a car before. With a Prius one should not be hauling rocks or pulling a trailer right. Does it give it longevity or something or can run at lower tire pressure or?
TomK

 

Thanks for the input usnavystgc. I was tempted by the Avid's, but ended up deciding to go with the Michelin Defender in the 185/65R14 size. I'm getting them in a couple days. It seemed like in the Tire Rack tests that the performed better overall than the other options. The other tire that looked close in terms of performance was the Sumitomo HTR A/S P01 (not available in the 175 size). Although the tests are a bit apples and oranges, since the car and tire size in the tests are close but not exactly the same. But still they rated the Defender highly and were comparing it to a slightly higher class of tire. And it's a LRR tire.

So we'll see how it goes. All of the tires mentioned in this thread seem to have complaints about wet traction, both in user reviews and Tire Rack's reviews. Of course it's also all relative, tires seem to continue to improve over the years. Then again maybe it's not really possible to get good wet traction in this narrow of a tire. The higher performance tires avaiable only in wider tires for bigger rims seem (at least some of them) to have much better wet traction characteristics.

Anyway, we'll see how it goes.

*

It's not exactly clear what the load issue is, if any, and why Toyota specified the special, hard to find, XL tire for the first gen Prius. (Indeed, I think I read somewhere that in Europe they don't specify the XL tire for this Prius, so it could have to do with different regulations. Although, I could be wrong about Europe, I didn't research that carefully.) If you want to understand the whole load question more, you really should read ChapmanF's posts on it. He's gone into way more technical detail than anything else I've seen.

G1 tire requirements | PriusChat
G1 tire requirements | PriusChat
G1 tire requirements | PriusChat
G1 tire requirements | PriusChat
G1 tire requirements | PriusChat
Above all same thread. See also:
Tire size: starts with a P, or not? | PriusChat

As far as I understand, part of the issue seems to be that the Prius is fairly heavy for it's size, both because of the battery and especially because of having both a gas and electric engine in the front. This puts a lot of weight on the front tires, hence the atypical specification to inflate the front tires two lbs more than the rear tires. Also, the load has to be calculated, according to ChapmanF, separately for the front a rear axels, so even if the four tires together have more than enough capacity, the front two tires might not.

That being said, ChapmanF shows in his posts that even the non-XL tires like your Kumho's can bear enough load, so he speculates in the second to last link that it may be that the extra stiffness of the sidewalls in the XL tires is meant to improve handling on a tall somewhat heavy car with pretty narrow tires.

The load capacity is an issue with any car. It's just that normally a car with the weight of the Prius would be larger and have larger tires that are rated for more load anyway. But Toyota probably wanted small and narrow tires to improve gas mileage. They could have just specified 185 tires and avoided the whole issue. And even 185 is a pretty narrow, by todays standards. But obviously the Prius is about mileage above all and so Toyota was making different trade offs than a manufacturer normally would with a car.

So it's the combination of a relatively small and narrow tire, with a unusually heavy for its size car that creates the demand for a tire with an atypical load capacity for its size. And that in turn is why there are so few choices.

Hope that makes sense and ChapmanF or others can correct me if I'm getting anything wrong.

 

I guess I should go out and check tire pressure.
Thanks for the links and clarification on my tire ignorance.
TomK