Yokohama Avid Envigor and Gas Milease Drop

The same ones we always recommend.

Nokian WR or WRG2
Michelin X-ice Xi2
Hankook H727 for milder conditions

I 'llbe testing the Michelin Primacy MXM4 in wet weather this winter but likely won't encounter much snow. I'm more interested in their claim of wet weather braking superiority.

 

Yes but LRR tires have been demonstrated to save up to 7.5% fuel and possibly even more.

Even a 5% saving would amount to about $250 over the life of a set of tires. It seems like false economy to save $80 on a set of tires that will cost you $250 in extra fuel.

 

I went by gut feeling since I drive a low number of miles but lets try some math out. Let me know if you see an error in my math.

Altimax HP $71 a tire.
Michelin Energy Saver A/S at $104 a tire.
$33 extra per tire to go LRR for similar performance (traction/handling/etc) and that is conservative since I'm not including taxes or other costs.

$33 x 4 = $132

For easy math I'll say $3 a gallon. I fully expect gas to get more expensive but I want to do a quick calc first and then we can play with the variables.

Also for easy math I'll assume 50 MPG. Plenty of variables here.

How many miles do you have to drive to save money? Man, the caffiene hasn't kicked in my math skills are not working yet. This won't be elegant I'll brute force it a bit.

1000 miles / 50 MPG = 20 Gallons per 1000 miles
7.5% less fuel used is 18.5 Gallons per 1000 miles (54.5 MPG)
1.5 Gallons * $3 = $4.50 per 1000 miles saved by the LRR tire
$132 / $4.50 = 29.333

So by that rough math If I get 7.5% fuel savings at $3 and 50/54.5 MPG I need to put about 30,000 miles on a set of tires before the LRR premium pays back.

If gas prices go up the miles put on the tires could go down. If I get better gas mileage to begin with I have to get more miles on the tires.

How many years will tires last until the dry rot? Maybe 5 years? Which means I have to put more than 6,000 miles a year on those LRR tires to hit the savings before I replace them. Will I actually put 6,000 miles a year on my car? Maybe. I've had years were I put less than 6,000 on it. I've had years where I've put more.

Oh and tires age sitting in the wharehouse. See Are your new tires really 6-year old ticking time-bombs? | Wise Bread

They are stamped

Tires Manufactured Since 2000
Since 2000, the week and year the tire was produced has been provided by the last four digits of the Tire Identification Number with the 2 digits being used to identify the week immediately preceding the 2 digits used to identify the year.

Tire Tech Information - Tire Aging – Part #1

The British Rubber Manufacturers Association (BRMA) recommended practice issued June, 2001, states "BRMA members strongly recommend that unused tyres should not be put into service if they are over six years old and that all tyres should be replaced ten years from the date of their manufacture."

The Altimax HP tires on the Saturn were made in 2009 so they were fresh when I bought them. If I bought a set now would I get more 2009 tires, 2010 tires, or 2011 tires? How good is the turnover on LRR tires? Will I get "new" tires if I go LRR? Probably depends on the size, brand, and gas prices.

I have no doubt that there are people that drive enough to make LRR tires a no brainer. I'd love to have LRR tires myself. I'm just not sure that'd I'd save enough gas to offset the increased tire prices.

I'm not saying I'm the average driver or the typical case. I'm just saying the decision for me isn't as clearly in favor for LRR as for someone that drives over 10,000 miles a year.

 

Fair enough dhanson865. I agree that the economics are a bit different if you don't get full treadwear out of the tire. I'm doing 33000 km per year, so I definitely plan to wear out a set of tires before they "dry rot".

Re the "turnover" rate of LRR tires, perhaps that's not the most important thing. Most LRR tires use slightly different materials in their construction, in particular a silicon rubber compound. It might be worth looking into the longevity (wrt aging) of this compared with conventional rubber compounds. You may actually find you get a double benefit from LRR.

Honestly I don't know if this is true or not for LRR tires, but I know that with scuba gear the change from conventional rubber (fins goggles etc) to silicon rubber made an incredibly large difference to their longevity. The modern silicon rubber types last many times longer before showing signs of perishing, compared with the old conventional rubber types years ago.

 

You state your case well and I completely agree with you in pure economical terms. It's simple, if you drive less than $10000 miles a year then the cost of an expensive LRR may not pencil out although there are other higher quality LRR that are lower in price than the Energy Saver A/S.

The take home message here is that everyone has to evaluate their particular needs when choosing a tire. For Dan, he chose specific attributes that priced him out of the cheaper LRR tires and left him with the most expensive version. Since he drives very little compared to some of us his choice to go with a non- LRR makes sense.

I must mention that besides the economic factors of buying tires one may want to consider the social and environmental factors associated with using more fuel..... That is why I paid a premium for my dB Super E-Spec tires. They were made using 80% less petroleum than a conventional tire and they are LRR rated.

 

Yeah you're right about the ethanol, about one extra MPG is all I'd expect. The inflation pressure wont account for the other 7 MPG, maybe another one MPG.

I'd say the main difference will be due to driving style and a favorable route.

 

I'm going to guess about 1-2 MPG gain for each 5 PSI over stock assuming you do much if any gliding/coasting maybe 3 MPG total running 48/45 vs 35/33.

I'd say 5% gain for the 100% gas so another 2-3 MPG there. Note it'll take several tanks to wash out the ethanol (more accurately to blend with and replace and for the computer to adjust over time). Don't expect wonders on the first tank. I used Ethanol-free gas stations in the U.S. and Canada to find the station I buy gas from but it only has US stations.

Where I'm driving and how I'm driving is a big part of it. I don't have a choice about where I'm driving. I'm literally taking the fastest route to my destination and I'm not "hypermiling" though I do watch the energy display and try to avoid overly aggressive starts and avoid using the friction brakes (have no idea if I do or don't I just try to brake gently)

Decent weather includes having the car in a garage at one end of the trip so no heat or air conditioning required for the first part of the trip. If you live somewhere really hot or really cold that'll eat as much or more MPG than the tire pressure will.

The only "aero" mod I made was to take the 16" unicorn antenna off the top and replace it with a $4 4" antenna from the local dodge dealership. It's very similar in looks to the non shark fin antenna I've seen on some Gen III Priuses but I don't know if those were stock or not. do not know if the Toyota dealer has a cheap 4" antenna but the Dodge dealer had it so that's what I did. http://priuschat.com/forums/gen-ii-prius-modifications/90527-cheap-shorty-antenna-works.html I expect it saves some gas but so small an amount it's almost unmeasurable though I'd be pleasantly surprised if you told me you got one and saw a noticeable difference.

So I'm guessing 5-6 MPG due to gas and tire pressure and 4 MPG due to garage/outdoor temps, road conditions, elevation, driving style and something like 0.x MPG (less than one MPG) for the antenna.

 

The tire inflation mpg enhancement is a tricky one to estimate. I've found that you may gain more mpg just from simple overinflation and the reduced rolling resistance but if you regularly employ hypermiling techniques which include a lot of gliding then the gains can be even higher. I believe this is why the mpg difference between my 17s and my 15s is so great. I am better able to hypermile with the 15s. If I just drove them like every other person on the road the mpg difference would.be smaller.

 

Before I did the math to see where the break even point was for 7.5% fuel savings. My rough math was somewhere around 6,000 miles per year.

Since then F8L started a new thread for consolidating tirerack test data and I did some analysis of fuel economy from their tests. My post in that thread goes into more detail but I'll jump to the results here.

205/55/16
Goodyear Assurance Fuel Max ---
Hankook Optimo H727 -2.59%
General Altimax HP -4.96%

185/65/15
Michelin Energy Saver A/S +4.74%
Goodyear Assurance Fuel Max +0.37%
Goodyear Integrity ---
Michelin HydroEdge Green X -0.59%


note the Fuel Max vs Green X are only 0.96% apart but we previously say they are 1.44% apart in the other test. That difference is primarily due to the differing tire sizes. Larger tires have more rolling resistance and generally weigh more.

I can't say exactly but I'm assuming size for size the Alimax HP vs the Energy Saver A/S is likely to be close to that 7.5% you mentioned. The raw numbers are over 9% but it's likely the larger size tires are amplifying the difference in RR.

So I'm still willing to say it's worth it for LRR if you know you'll drive the car more than 6,000 miles per year and have the extra money for the up front cost of more expensive tires.

The Optimo H727 does well for a non LRR tire. Plenty of reasons to consider it.

I just wish we had apples to apples fuel data for the AVID ENVigor to fully put this to rest. Comparing it in a high accuracy test vs the Alimax HP or the Assurance Fuel Max either would be a good control for comparison.

 

PC member "the critic" got me to looking at the ENVigor again today. Found the PDF that mentions the RRC of the ENVigor and several other tires.

Now the PDF has the RRC in percentages such that 100% is the best tire so we don't have the raw RRC result but we can use this to make further comparisons should we find other data that overlaps.

Michelin Primacy MXV4 100
Yokohama AVID ENVigor 81
Michelin Pilot Exalto A/S 78
Bridgestone Turanza with Serenity Technology 71
Bridgestone Potenza G019 Grid 63

taken from http://yokohama-media.unitedfuture.com.s3.amazonaws.com/1313088868-yokohamatire_avid_envigor.pdf

 

fwiw I finally replaced the AVID ENVigors. I got Michelin Energy Saver A/S (All-Season) but I went 195/65/15 vs the 185/65/15 I was looking at a couple of years ago.

after seeing all the threads on how hard it is to find these tires I got prices from 3 different stores in town and had them installed the next day after calling. Tires were produced week 52 of 2013 so they do seem fresh.

It's below freezing right now so I have weather to wait on while I break in the new tires. I'll be looking forward to spring/summer/fall to see what these tires can really do.

I replaced the rear shocks/struts while I was at it and got the alignment checked (the toe was off on 3 of the 4 tires)

So it won't be apples to apples between the suspension refresh and the alignment changes.

I don't know the exact mileage but it seems like only 30-35,000 miles on the ENVigors. They were near the tread warning bars when I replaced them.

Honestly if I couldn't have gotten these I probably would have gone for the Michelin Defender just so I could go 205/60/15 and be at 842 RPM vs the 832 RPM I got at 195/65/15. Either way I expect a more accurate speedometer than I had at 185/65/15 and 850 RPM.

Now I'm just waiting to a few hours for the tires to cool (in garage that is about 50F) to check and see what pressure the guys in the shop set the tires at. It says 35/33 on the receipt, if that is accurate I'll be adding air tonight.

 

Hope you like the new Michelin's as much as I like ours. Got the standard width here. Have put around 8000 miles on them so far I think. Seem a lot better than the OEM Integrity. Glide easily and great MPG. Saw a difference right away in the numbers. It seems like it took a few tanks of fuel for them to break in fully, but really did not see a big drop in MPG.

Good luck to you.

 

Checked the tires and the front left and front right were off by 5 psi. Something like 33 left vs 28 right. I'm not sure how on brand new tires you mess up the pressure like that. I'm assuming that 3+ hours on 50F concrete indoors is enough to evenly cool the tires (hmm the side that was lower is on the side exposed to the outside air, let me go get the temp gun*).

Aired them up to 45 front, 42 rear, The gauge on the pump and my handheld gauge agreed within 1 PSI or so. Of course that mixed oxygen and other gases back into their nitrogen fill but I figure I'm better off with proper pressure than ideal gas.

I also don't think it's worth a trip back to the shop to get them to fill it for me, especially considering they would be adding air to hot tires after I travel 6 miles to the shop. The tires would heat unevenly on the way and unless they are willing to overfill and let me even out the tires afterwards it'd leave me in a similar situation after the tires cool.

*edit, the temp gun shows the concrete by the outside of the building at 54/55 degrees and the concrete by the drivers side tire at 57 degrees. I suppose that might account for a slight discrepancy from left to right.

I guess I'll check the pressure again next weekend when I can let the car sit longer and try to find a warmer time of day when the concrete is closer to even with outside temp.