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Congrats! Wait until temps get over 70F and everything is fully broke in. You'll really see mpg tick up.

Given your need for a tire with excellent wet traction, good fuel economy and good steering feel I would say check out the PureContact. I had them for awhile but I didn't like how rough they felt. It turns out most of the rough ride was due to them being an XL tire in my size (205/50/17). I switched them out for the Primacy MXM4 again in a smaller non-XL size and the ride was a little better but steering response was more vague. It also seemed like mpg went down slightly with the MXM4. Both tires had less than 1,000 miles on them during the testing. If the PureContact lasts the full 70,000 miles or close to it then you'll be doing well economically speaking. As will any high tread wear LRR tire I would not expect a ton of launch traction so expect a bit of spin with all of that TDi torque. :) http://www.tirerack.com/tires/tests/testDisplay.jsp?ttid=166

Congrats! Warm weather is awesome! :)

Aye, different pumps and different pumping techniques will alter the amount of fuel pumped each time. It is best to either: A: Just believe the dash readout and be happy. B: keep a log and after 10 tanks or so perform the calculations to figure out the average % difference between hand calculations and the dash read out. Then just assume that your dash reading is +- whatever your average percentage differential. LOL

Aye, I considered that. Some of the former Prius owners were also getting "really low" numbers in the new car where they had no trouble getting EPA in their old cars. Still, I know there is a learning curve. I also think that Ford will adjust programming to reduce highway EV use and increase efficiency. I think the FE questionnaire is a great idea. It helps weed out those who are truly seeking help and those who just want to complain. :) That definitely helps but you still have to contend with heat seat of interior materials and the 20F+ temp differential between inside and outside temps. Maybe the CMAX AC system is more efficient and this will not be such a big deal. Watching the 7-10mpg drop in my Prius was gut wrenching for the 10+minutes it too for the AC compressor to wind down. I'm sure you've seen my YouTube video of the drop. lol I'd be happy to post my thread on reducing the hit of AC on mpg if you think it would help. I'd need your help with the CMAX specific though.

What size 18" or what year Passat? I'll see what I can find. Most 18" tires are not really LRR despite manufacturer claims. :(

It would be interesting to test this idea in a CMAX. In a Prius it is more efficient to roll the window down, even at highway speed as the A/C can pull 1,500-1,800 watts of power to cool the cabin down initially then 300-600watts to maintain temps. That's quite a bit of power. It translates into a 7-10mpg loss for the first 10min or more while the cabin tries to cool. I've monitored this quite a bit on a Scangauge and Torque app. Conversely, rolling down a window has almost no detectable effect. I'd be very interested to see how it works on the CMAX. We temps are over 95F, battery temps do tend to rise above comfortable levels and I agree that the A/C should be used. No sense in prematurely killing your battery just to save a tiny bit of fuel. :)

Are you sure your Golf TDi doesn't have the ProContact? The PureContact actually has better initial steering response than the Primacy MXM4 but the ride is worse. The ProContact is a different tire. My friend just bought a Golf TDi and hers has the ProContact. :) I up sized from a 15" tire to a 17" tire when I first went with the Primacy MXM4 so the loss in mpg was mostly due to the upsize. Prius drivers whose car came equipped with 17" Toyo Proxes A20 tires seem to loss about 2-3mpg when swapping to the MXM4. On the other hand, the MXM4 is OE equipment on the Prius Performance Plus package and the Lexus CT200h. My significant other's 2013 Acura RDX also has the MXM4 as OE equipment. When a Prius upsides to a 17"-18" tire from the OE 15" tire they tend to lose 3mpg-8mpg depending on the combo they choose. Hypermilers suffer even more of a loss. In the 17" sizes I tried I found the Ecopia EP422 and Continental PureContact to be the most efficient but they didn't offer the Energy Saver A/S in a Prius 17" tire size (215/45/17 or 205/50/17).

I really like the Primacy MXM4. I've had them twice on my Prius in the form of a 215/45/17 tire and they are fantastic. Not the most efficient but like you stated, they are safe in wet conditions. Fortunately most of the new LRR tires are very good in wet weather conditions. The Continental PureContact and ProContact are good examples of this. The Turanza Serenity Plus is another tire I would consider along side the Primacy MXM4 (not to be confused with the older Pilot MXM4). You are 100% right in your method of determining your primary needs then seeking out the most fuel efficient from the top tires that excel in those needs. :)

Only the adults pass me. I smoke the kids on tricycles! :p

I forgot to add that rather than use the UTQG number for tread wear, I look at the warranty for each tire because that is what will affect your ability to get money back on a tire that didn't last as long as the manufacturer said it would. *Edit* So the Energy Saver A/S is listed at 55,000 mile warranty and the a Defender is 90,000. That makes a larger difference than I expected so you may be on to something. The Defender is a T rated tire vs. the V rated Energy Saver. I would expect performance to go down but fuel economy to go up. This is an interesting change from the Prius sizes. Anyone feel like doing some testing on their own dime? LOL

Good eye! there are a lot of specs to consider. However, the UTQG doesn't tell you how efficient a tire is. It simply tells you the traction grades and the manufacturer's rating for tread wear. One must also note that tread wear numbers are subjective and may not translate between manufacturers because they determine this number privately and it is not verified independently. So a 600 UTQG from Michelin may be the same as an 800 UTQG from Continental. In the case of the Defender, it is a pretty darn good tire but it is MUCH less efficient than the Energy Saver A/S. so while you have a longer lasting tire, you also get worse fuel economy with it. So much so that the tire would need to be quite a bit less expensive to pencil out in the long run. In the case of Prius-sized tires the a defender does not pencil out and only makes sense for those driving 20k or more a year. Otherwise, a person driving 10k a year would end up with a dry rotted unsafe tire long before they wore the tire out thus it cost them more than a more efficient tire that wears out faster but still over 65,000 miles. One must also consider the fact that manufacturers often rate their tire's traits against other tires in their class from that same manufacturer. For example, the Energy Saver A/S is rated as a 10 in fuel efficiency as is the Primacy MXV4. We know the MXV4 is nowhere near as fuel efficient as the Energy Saver A/S though. So what gives? The answer is the Energy Saver A/S is within the passenger car all-season tire category and the Primacy MXV4 is in the luxury car all-season category. Two different classes of tire and thus different comparison ratings. The MXV4 is very efficient compared to other tires in that class of Michelin tire but compared to the Energy Saver A/S it should be rated at an 8 or lower. As for the price difference between the Defender and the Energy Saver A/S (ESAS), I show the a defender at $151/ea and the ESAS at $174/ ea at TireRack.com. I've done the math for the Prius tire size and it comes out somewhat close as the tires are very similar in price. For the CMAX size the price difference is larger so it may be a tighter competition. I need to know more about how the CMAX responds to less efficient tires before I could say anything worth typing. :)

A vehicle purchase is a very personal choice. Those looking for Max Efficiency would lean toward the Prius and live with lackluster performance which is what I did. Those who are not willing to make such sacrifices would look at a CMAX. I looked at the CMAX when it came time to trade in my older Prius but after living in the 55+mpg range I couldn't stomach dropping down into the higher 30s or low 40s. Throttle response just doesn't interest me as much now as it did in my racing days. :) Still, the Prius has enough power to get out of the way and to merge without issues. Years of drag racing has left me jaded such that anything short of a 12sec car is not exciting to accelerate in anyway. So yes, a Prius, any Prius, will easily trounce the CMAX in fuel economy at any speed BUT is it as fun to drive? That is up to the driver. For you, and the majority of the world, I doubt it would be. For me it is because I would cringe at the lower fuel economy. :) Given your criteria I think you made a great choice. You also have a much richer interior which I am admittedly jealous of. ;)

You will love the summer mpg in these cars! Winter is notorious for dragging down fuel economy in hybrids. Well, all vehicles really but in hybrids we tend to notice it more because a 10% loss at 47mpg looks a lot larger than at 18mpg even those the percentage is the same. If you can restrain yourself from blasting the A/C system at max you will be rewarded with excellent fuel economy during the summer for the following reasons: 1. Rolling resistance in tires decreases dramatically as temps rise into the 80s and 90s. 2. Warm up times decrease. This is a huge benefit for those making short trips. 3. Air density decreases which is good for high speed driving. 3. You don't need to use the heater or defroster. During the summer I tend to leave the A/C off and instead use the flow through method. Crack the driver side window about 4"-8" and crack the rear passenger side window 2"-4". That is enough to allow air to flow through the car and cool things down somewhat. If you can run your vents without the A/C that helps too. If it gets too hit and you are really serious about mpg, simply use the flow through method but roll the driver side window down completely and stick your arm out so that air flows through your shirts arm hole. lol For serious hypermiling only. On shorter trips, the A/C can put a serious dent in fuel economy!

My pleasure, Riddley. Here is one way to try and calculate the cost per mile for a tire so that you can make a comparison. The only hitch is not knowing exactly how much more efficient one tire is than another. To help provide confidence in that number you can use TireRack's tests. In this example we will use TireRack's test "When Round and Black Becomes Lean and Green". http://www.tirerack.com/tires/tests/testDisplay.jsp?ttid=121 We will compare the Michelin Energy Saver A/S and the Goodyear Assurance Fuel Max tires. In this test the Energy Saver A/S was approx. 4.26% more efficient. I'm going to use the Prius average numbers because I am confident in them. A CMAX owner can simply deduct 4.26% from their current average mpg to come up with the Fuel Max number. The math looks like this: Tread wear warranty (miles) / mpg = # of gallons * $3.60 (ga of gas) = cost of fuel for the life of the tire + price of tires / tread wear warranty = total cost per mile to drive on that tire. Example: Energy Saver A/S 65,000 / 53.8mpg = 1,208ga * $3.60/ga = $4,349 + $626 (4 tires) = $4,975 / 65,000 = $.0765 cents per mile Assurance Fuel Max 65,000 / 51.6mpg = 1,259ga * $3.60/ga = $4,538 + $496 (4 tires) = $5,030 / 65,000 = $.0773 cents per mile So in this example, the Fuel Max tires were much cheaper to purchase but in the long run, the Energy Saver A/S was cheap to own. Now price is not and should never be your only consideration when buying a new tire. Safety should come first so you wouldn't want to sacrifice braking grip for mpg but you may decide you care more about fuel economy than handling. You may decide you need better wet weather grip or snow traction. Comfort may be your highest priority. That is where spider charts come in. These charts plot tire characteristics in such a way that you can choose the traits that interest you most and see how a tire you are considering stacks up in those traits. Unfortunately the cannot make a tire that does everything extremely well. I say choose a few traits to excel in and live with worse performance in the rest. :) Example of a spider chart in a tire test. These tires are relevant to CMAX owners because these are quality tires that come in the 205/50/17 size. Hint, the Turanza Sernity Plus is a pretty nice tire but notice it sacrifices a big of fuel economy over the PureContact. http://www.tirerack.com/tires/tests/spiderChart.jsp?ttid=166

Unless you mean used take-off prices when you say "street prices". I'm not sure what you mean by that. I generally use TireRack.com as a baseline for pricing although I usually shop at Costco and America's Tire (Discount Tire).

$174/ea. before the $70 rebate if up you buy 4 tires. The $70 rebate usually puts the Michelin tires into competitive level with other quality manufacturers like Continental, Goodyear, Bridgestone etc.. Unless those manufacturers are running their discounts at the same time. :) It could be possible to find a lower cost per mile tire in the 225/50/17 size (maybe the Goodyear FuelMax) but you would likely make some sacrifices to do so and you'll still show a lower mpg number which for some of us is almost more important than to total cost to run the tire. LOL

We don't all drive http at that. ;) Well, I do tend to drive the speed limit when traffic is around or 5mph under when alone. The difference in FE from 65mph to 60mph could mean the difference between a 60mpg trip and a 55mpg trip in a 2010+ Prius liftback. FWIW, we do not promote annoying other drivers with hypermiling antics. It's just not safe and it's not worth the fuel/money saved. However, driving the speed limit in the furthest right lane available is perfectly acceptable and if someone else doesn't like it then too damn bad. :)

I decided to start this thread in the hope of keeping members from swapping their tires in an effort to find better fuel efficiency and/or to warn those looking for better grip or handling without being aware of the possible negative consequences. The Energy Saver A/S is one of if not THE most fuel efficient tire we know of that is available in North America. Tests from TireRack.com has priced this as has my own physical testing and research. Compared to the OEM tire for the Prius, the Energy Saver A/S is approximately 5%-6% more efficient. TireRack testing showed a 3.8mpg increase over a fairly efficient Michelin Hydroedge and almost 3mpg more efficient than the OE Goodyear Integrity. My own testing averaged a 2.5-3mpg gain vs. the OE Yokohama AVID S33D. There has been tons of posts on the Prius forum regarding the newest crop of LRR tires and thus far nothing really beats the Energy Saver A/S in terms of efficiency and lowest cost per mile while maintaining adequate grip, braking, longevity and comfort. The Bridgestone Ecopia EP100 was nearly as efficient but it has been discontinued and the Ecopia EP422 doesn't handle as well. My point here is to make you think carefully about your next tire. As many Prius owners have found out too late, the OE tires are pretty efficient and going to a conventional non-LRR for added performance can really ding your fuel economy. For us it can be as much as a 3-5mpg drop (50 to 46 avg.). Because the CMAX already starts off with the most fuel efficient tire, the loss could be quite high for you. I'm not a tire expert but I spend quite a bit of time researching fuel efficient tires and testing them when I have the money. If I can help you guys like I've helped my brothers and sisters on the Prius forums feel free to ask. I have created threads comparing tires and links to tests done by TireRack. If there is interest I would be happy to create one her for CMAX owners. :)

Keep in mind that this was for the GenII and GenIII Prius. The CMAX could be different because of aerodynamic differences. :)

Hi Bob, While my tests on the above subject were not very scientific, I did try and minimized other variables as much as possible including elevation, surface type, wind speed and direction, weather, etc.. I found that having the driver's side front window and the passenger side rear windows completely down had a very minimal affect on mpg. I could not dectect a notiecable difference amongst the "noise" from variables like road surface undulations (small dips in the road). On those same exact stretches of road I would observe the 7-10mpg drop when switching the AC on. I found that cracking the driver's side front window about 3-4" and the passeger's side rear window about 3-4" was enough to create airflow through the cabin. When temps are less than 100F I found this to be sufficient for cooling purposes although it is still quite hot inside the car. For hypermiling reasons this is just something you deal with. The other option is to roll the driver's window down completely and stick your arm outside the window and let the airflow go through the arm hole in your shirt. :) I created a thread on minimizing the impact of AC on mpg. I will compy and paste it here so I don't have to link you off site. Ok since the loss of MPG through the heavy use of the Prius A/C system has become such a big subject I thought it would be nice to have a thread that focuses on mitigating or reducing those losses. I have posted some basic ways in which you can reduce the losses but I am hoping those smarter and more creative than I can help me expand the list so that other Prius owners are able to benefit from our knowledgebase here at PC. Problem: Heavy A/C usage in hot climates and significantly reduce your average MPG. Why? The A/C system is electric and therefor requires energy. The energy essentially comes from your HV battery which then requires recharging. The energy for recharging is supplied by your ICE which runs on gasoline.A/C systems inherently run less efficiently in hot temperatures. The hotter the ambient temperature the less efficient the system is and the harder it has to work to reduce temperature inside your car (or house).The temperature inside your car is often much warmer than the outside ambient temperature by 30 degrees or more depending on many factors like interior color, number of windows and their construction, etc.. The A/C system has to do a lot of work to reduce those temperatures to your desired temperature. Imagine trying to reduce the temperature inside your car from 130 degrees to 70 degrees. That is a lot of energy! Where does that energy come from? Ohh yeah, gasoline! The lower your temperature setting, the higher the energy required.I have measured an 1800watt continuous draw for over 10min while the A/C tried to cool the car! Even after 30min the draw was over 600w. This was measured by Torque app in my GenIII.Methods for controlling heat buildup in your car: Park in a shaded area. Under a tree may help but a better tactic is to park on the eastern side of a large building. As the sun moves to the west in the later portion of the day, the building will block the sun from hitting your car. With your windows cracked, the heat from the earlier part of the day will dissipate faster than if you parked your car in the full sun the entire day. Crack your windows a few inches to allow warmer interior air to vent outside the vehicle. Assumes you are parked in a safe area Tint your windows Use a high quality windshield sun shade. Priuschat shop has a very nice one! If you cannot park on the east side of a building try parking your car facing the west and use a quality windshield sun shade. This will reduce the number of windows directly facing the sun and thus not allowing as much of the suns radiation to enter the car. Drive the car for the first few minutes with all the windows down to circulate the hot air and direct it outside.Best Practices for A/C usage and maintenance: Use the A/C sparingly or use the crossflow venting technique (see below) Crossflow Venting - Roll the driver side window down approx. 3" then do the same for the passenger side rear window. This will create a nice cross breeze and will not adversely affect aerodynamics in a noticeable way. In the event this is still not enough, roll the driver's window completely down and stick your arm outside the window. This allows wind to flow through the arm hole in my shirt and flow out through the other arm hole and the bottom of my shirt. This can dramatically add to the the cooling effect and is still more efficient than running the A/C , even on the freeway at 60mph. Use a setting that is high enough for maximum efficiency but makes you comfortable. 78 degrees seems to be sufficient for most drivers Ensure your A/C system is charged to spec levels and operating efficiently. i.e. condenser is clear of obstructions, bugs, etc. Use Eco Mode if your car is equipped with the featureThese tips will not only help reduce the fuel economy hit of the A/C system but it may also extend the life of your HV battery by reducing interior temperatures while the car is sitting in the parking lot. If your interior is 130F then your battery may be too! When outside temps are over 100F it is recommended to run your A/C on longer trips to try and cool down the HV battery. I've measured a 15F difference between ambient temps and battery temps when the A/C was running. After turning off the A/C the battery quickly returns to near ambient temperatures. Fuel economy is important but your bodily well being and HV battery life are more important. Read more: http://priuschat.com/threads/how-to-reduce-mpg-loss-because-of-a-c-use.97814/#ixzz2KbpPLITy

Agreed. In testing with the Torque App, myself as well as three other PriusChat members, recorded near instant draws of 1500watts-1800watts when outside temps were over 90F and the auto AC temperature was set to 78F or lower. This draw stayed at 1500w to 1800w for 5-10min at least before the cabin temp started coming down and got close enough to the set temperature to ramp down the compressor speed. Even after 30min on the freeway I was observing a 600w draw. Now you can imagine what such a daw would do to fuel economy if one made only short trips in which the AC was working at full capacity the entire driving cycles. eek!

As the driver in the video above I can say with certainty that I did not adjust pedal pressure during the video. I've done this test dozens of times to ensure I wasn't somehow causing the decsease in mpg by pedal pressure or changes in surface grade. You have to understand how the electric AC and hybrid system works before you can make claims of deception. My standing at PriusChat and other forums is too important to me to try and pass falsehoods. Besides, what did I have to gain by lying? I'm just trying to add to the hybrid knowledgebase. :) Plus 3 Golfer pretty much covered the rest.

Rain can have a huge effect on fuel economy. Water on the road increases rolling resistance. Large amounts of water will significantly increase the amount of horsepower required to maintain a desired speed. Next time you drive through a puddle notice how quickly your car slows down. It takes a lot of energy to pump water through your tire tread and move it out of the way and/or throw it into the air. That energy came from kinetic energy which ultimately came from gasoline. If you think rain has no effect on your fuel economy then I would suggest researching the subject and monitoring your mpg more closely. :) http://ecomodder.com/forum/showthread.php/effect-wet-roads-efficiency-estimated-14-5-mpg-109.html http://www.cleanmpg.com/forums/showthread.php?t=14422 http://www.foxnews.com/leisure/2012/08/03/getting-better-gas-mileage-in-warm-weather-here-why/