LRR tires. Unicorn of the future?
 

So. tires on my Metro are pretty bad, fronts are ok but the rears are ready to come apart. started researching tires. found a cheap set of 12"ers for $46@.

Eventually my research crossed LRR tires. Looking for every edge I can find I bit the hook. A bit of research came across a blog declaring Michelin Energy Savers as the king of LRR tires with a 9% increase in milage for the low low price of $153 per tire for the smallest available, a 195/65-15, Got me onto the path of thinking. How long before these tires actually pay off?

After doing some math, to be fair, I found a set of cheap 195/65-15s for $76@ so that "size" would not be an issue.

these are my findings

Control Tire LRR Tire
$ 76 $156 each
$304 $612 per set
$308 Differance

Now I have to make certain assumptions at this point, since the value off the LRR is given as a % of overall mileage the starting mileage is moot. I use 40mpg as base. I also assume 10,000 miles per year driven. I seem to recall that as "average" from somewhere. Also I ended up using $3.75 per gallon. Gasoline prices fluctuate 1) over time 2) geographically. so 40 MPG plus 9% mileage gives the vehicle with LRR tires 43.6 MPG.

Miles per year MPG Fuel fuel cost per year
10.000 / 40 * 3.75 $940 Control tires
10.000 / 43.6 * 3.75 $860.09 LRR tires
$ 79.91 Savings per year
Differance in cost, Savings per year
$308 / $79.91 3.85 years to break even
37,000 Miles to break even

To me. this means you should buy LRR tires IF you have plenty of disposable income AND you're ecomodding to A) cut the drain of resources on the planet or 2) are simply trying to gain the best fuel mileage possible. but if you are looking to cut personal costs, and don't plan on owning your car for near 4 years, go with normal tires.

Now. I am just an addle minded ex-painter stroke victim, and to be fair. painters are painters, and not accountants, for a reason. so. My math may be off. or, my equations for that matter. If so. please shed some light and feel free to correct my sorry excuse for math. my above math is by no means all inclusive and I'm aware different tires have different rolling resistances/costs etc. I just posted what I found after a short period researching on the internet (Google FTW!).

I looked on Tirerack.com and found the Michelin Energy Savers for $96 each and a reasonably comparable non-lrr Michelin Harmony priced @ $107 each. This would make the payback instant.

Comparing the cheapest set from some unknown brand to a Michelin is kind of an apples to oranges comparison.

Also Honda Insight owners swear that the factory Bridgestone Potenza 165/65R14 are great mpg tires and can be had for $87 a pop from tire rack. These might be a closer fit than going all the way up to a 15" tire.

Kirk

yeah, the irony is that the tire I reviewed, that looked to be the smallest Tire in the energy saver line, wont fit on my car.

As I stated, My findings where not all conclusive. I Didn't look for he cheapest available tire, Simply what I could find in short order.

The Bridgestone Potenzas are known for 1) high mileage good fuel economy and b) terrible performance (breaking/ cornering type go fast stuff), they might BE LRR tires without being classified as such. (anyone know if there is a standard for what qualifies as a LRR tire?)

Hmm at tire rack I found the "Micheline Energy Saver A/S" (All season) for $96 per, but no sign of the plain "Energy Saver", No clue what the (if any) differance would be between the two. The sight I originally went to (America's Tire) Labeled it only as Energy Saver, the A/S version (In the above 195/65/15) was $115 per and didn't list a price for the Harmony.

They are different tyres, with the A/S being sold in the US having more siping and a different thread pattern than the Euro Energy Saver (which is also on sale in Canada, IIRC). Dunno about the A/S, but over here the Energy Saver is available in smaller sizes than 15" 195 wide.

It's not a unicorn, as I've gotten 7% better mileage with them, coming down from equally wide 17" tyres (on heavier rims).
It doesn't look like putting 37.000 miles on them would be a problem either - and I even have them in an unnecessarily high W speed rating. :rolleyes:

As for swapping 12" wheels for 15" rims ... I wouldn't do it.
Their weight is most likely going to kill the deal in mixed driving.

Sure, you can go up in size, just don't overdo it and watch the weight of the new wheel+tyre. The effect of the larger rim's weight is going to be bigger than that of having less rubber on a lower profile tyre.
You don't want to go up much in weight - preferably, reduce their combined weight.

13 or 14" can do fine, if you select the rims & tyres.
MetroMPG has tested the RR of various tyres :
http://ecomodder.com/forum/showthrea...eet-19126.html
but that doesn't test the effects of the rims themselves, nor their size.

A good combo would be a low RR tyre on a really lightweight alloy rim, like the RE92 MetroMPG used
BTW :
Some alloy "lightweight" wheels are actually heavier than simple steel rims .

40mpg is already pretty high Ultra-Orange. Do the same math with a 30mpg car, and you'll break even much sooner. Do the same math with a 50mpg car, and you'll break even much later, due to diminishing returns.

Your math is pretty sensible, but I want to say 2 things: First I think that the initial 9% claim needs substantiation from Michelin. What tire are they comparing to? They probably compared it to a second leading tire in that class. Secondly, I think that LRR tires have a dual effect for hypermilers - the first of course being lower resistance to get (and keep) the car moving, but the second being the potential for longer coasts. That is why I believe that hypermilers have the potential to see better gains from LRR's, if they take advantage of them.

I suspect that LRR tires are a nice 'set it and forget it' ecomod for people who are uninterested in hypermiling, or don't know about it - even if they aren't drastically better, financially speaking.

That's interesting that you sat down and did that cost/benefit work. I'm sure plenty of consumers would not have bothered!

Thank you both, Euromodder and Kodak. I really kinda went into rant mode when looking up this information. My "Research" was pretty basic and I used math that kinda sorta made sense. Kinda feels good to be dis-proven in a calm rational way. Guess I'm to used to Video game forums where "Lol noob" tends to be the logic of the day.

Did you just compare the cost of a 145 R12 tire to the cost of a 195/65 R15 tire? those are over 3" taller and 2" wider then a 145 R12.
In case I am missing something, you can get some low rolling resistance tires in that size for $75 each, Tire Search Results

Or if you are looking for something that will kind of fit your geo metro, altho still to big you can get some 175/70 R13 LRR tires for $57 each at just over an inch wider then stock and over an inch taller.

Kumho eco Solus HM KR22

or the 165/65R14 tires that the Insight uses for $87 each, altho they are still an inch taller then your stock tire and 3/4" wider then your stock tire.

But if you really do want something that is the stock size for your Geo Metro, try finding a Zenn neighbor hood electric vehicle dealer or other NEV dealers and get some tires from them, nice quite, LRR tires in 12" and 13" sizes.

Ick! Yeah, I'm familiar with "experts" who are more prepared to tease you than help you. Not in video games necessarily, but forums in general.

Truly passionate people usually like to share information and encourage other people to learn by asking questions. You can spot a phony by seeing how well he or she interacts with newcomers.

No. The prices I quoted above where for a same size tire as the Energy saver. I should have been more clear. I found a set of 145/12s for $46 per. Coopers I think. So I had $46 in my mind when I found the Micheline Energy savers at $153 per. and THAT set the ball in motion. so I took the smallest Energy saver that the sight had listed and compared it to another 195/65/15.


Hope that clears things up and thank you for the tire comparisons! For the metro I'm just looking for something that will fit on the car, if it ends up saving me gas in one form or the other, Bonus!