Success with LRR Michelin HydroEdge tires +6.3% MPG
 

I just did a test of changing nothing but 4-tires.
Depending on the types of corrections used for the data, the lowest measured gain is 6.3%. Others may see a little larger gain depending on how you run your test and the types of correction factors used.

Keep in mind this was a swap from four old worn Douglas radials to four brand new tires. All testing was done at 50 PSI, and highway test loops were used at a speed of 55 MPH using cruise-control. Conditions monitored and data collected with two Scangauge2's, and a Davis weather station computer, with final fuel usage determined at the pump at the end of each loop. I have 4.5 years of data collection on this car previously and many of the same type test loops performed in the same way and in the same location for this car and several other vehicles. The testing error range on this particular car is a little under 1%, so I don't feel the need to run back-up tests on this, nor would I remount the old tires for a test.

The Michelins are significantly heavier than the Douglas tires.
Size for both sets is 195/60-15 (stock for Ford Focus)
Douglas tire = 15.8 lbs each
Michelin tire = 21.8 lbs each

The Michelins have a very deep tread ( 9mm ) for such a small tire, and are quite stiff, which I'm sure accounts for the extra weight. They seem much better made all around than the Douglas brand.
They ( Michelins from Tirerack ) cost around $100 more per set than Wal-mart's cheapest, but are supposed to perform really well in wet conditions, and I consider the safety factor worth it even without the mileage improvement, so I'm obviously satisfied with this choice in tire.

Depending on corrections applied the test results ranged from a low of
+6.3% to a high of +6.8% MPG.

Again this was old vs new tires with a significant difference in weight change involved. It's not exactly what you could call a fair test between the two tire types, but the vehicle did achieve a new high in MPG for this test loop, so indications are that these tires do perform as they say they do.
I'll have to update my vehicle data when I get some free time.

Congrats on your results & thanks for posting.

Did you buy them primarily for their wet abilities, and the efficiency improvement was an unexpected bonus?

You got about as much improvement as I got (6.9 %) when I changed from regular to Energy Saver LRR tyres.

I didn't change from well-worn tyres though - which would have worked in favour of your old tyres.

The good thread depth should make 'm last long.
I'm starting to worry that my car will wear out before the Michelins do - and I have yet another set laying about.

Just talking economics, have you crunched the numbers to see the break even number of fuel economy vs the extra price of these tires over WM tires...how many miles does it take?

Well, I was a big fan of Aqua-treads but I can't get them anymore, so I've been on the lookout for something similar, and I have also been looking at LRR tires, so this choice seemed to make sense. I can't say it was the primary factor, but more like half-n-half. I have yet to drive them in the rain, but the old worn out tires were pretty bad in rain, especially at anything over 40 PSI. The older I get the more that sort of thing bugs me.

The great tread depth was the unexpected bonus. Tire-rack had these listed with LRR tires, which is how they got my attention initially.
I'm not sure how to judge the added mass of the tire, but I suppose it could actually help a little when using cruise-control on the highway by conserving some momentum during the small throttle transitions.

Sorry I didn't see this, but yeah I did.

With 40 MPG it takes 15,000 miles to recoup the difference @ $4/gal.
With 30 MPG it's around 10,000 miles @4/gal.
With 20 MPG it's around 8000 miles, and so on.

Obviously IF the price of fuel goes up, the return is sooner.

There is also the hope that these tires will last longer than the last ones due to thicker tread & stiffer design.

I drove the car in light rain this morning and it felt very solid.

Here are the photos:
Focus - New Michelin Hydroedge tires pictures by olympiadis3 - Photobucket

http://i702.photobucket.com/albums/w.../DSCF6134b.jpg

this thread give me great hope! I'm currently on some BFG G-Force Sport tires and they don't roll very well. I hope to upgrade to 20mm narrower LRR tires in the near future. (205/50 to 185/55) :thumbup:

good looking tires. I'm starting to research what to get when mine wear out. I've always bought goodyear viva 2's...not a LRR tire but they always wear out well before the mileage warranty so I always get indefinite free replacements. I'm wanting something different though because the viva 2's are loud on the highway.