Choosing Fuel Efficient 15” Wheels and Tires

[Top_Fuel]

I like my new Mirage, but the stance of this car is absolutely killing me. These cars look seriously funky on the stock wheels/tires. Do I really have to putt around on these things to get great gas mileage? I’m about to do a 15" wheel/tire upgrade and find out!

I only have about 700 miles on the car so far...and it's averaging 50+ mpg with conservative driving. If I can maintain that mileage with better looking wheels/tires, I’ll be satisfied. Remember...my goal isn't to find the biggest wheels/tires I can fit on the car. I'm looking for larger size while maintaining respectable MPGs.

NOTE: If you don’t need the details, just go to my Fuel Efficient 15-Inch Wheels and Tires thread.



Goal: Upgrade to 15” wheels with minimal impact to fuel economy

Here's my approach to reach this goal:

• Minimize the weight of the wheel/tire combination
• Use the best low rolling resistance tire available

3 Reasons I'm Upgrading to 15" Wheels/Tires

Here's why I'm looking for new wheels/tires when my new car isn't even broken in yet...

1. OEM wheels/tires aren't helping the car's appearance

A Mirage looks oddly top-heavy on narrow wheels with excessive offset, and tiny tires. I'm a car guy...and in order for a Mirage to look even remotely cool, the stock wheels/tires have got to go!


2. OEM tires are marginal

Enasaves have no redeeming qualities (other than low rolling resistance). They have average traction, short tread life, and fragile sidewalls that are easily damaged. At $120/each (plus installation), nobody would ever put these tires on their Mirage if given a choice. With no road hazard warranty, these tires are one big pothole away from becoming an expensive problem. I'd rather sell my Enasaves now while they are new...and use those funds toward higher quality, longer lasting tires that will be covered by a road hazard warranty.


3. Low Rolling Resistance 14" tire choices are extremely limited

There are no 14" tires available with low rolling resistance and a long tread life. If you drive a lot of miles, you want a tire with both qualities to minimize operating costs. A $35 tire that only lasts 20K miles and loses 2 mpg will ultimately cost more over time than a quality, long-life LRR tire. When it comes to tires, you generally get what you pay for.



Tire Selection

Here are the main pros/cons of the three 15" tire sizes I considered...

#1: 175-55-15
Pro: Same diameter as 165 Enasave
Pro: OEM size on optional 15" Mirage wheels
Con: Poor selection of LRR tires in this size
Con: A very uncommon tire size in the US
Con: Fits best on more narrow 6" wheels

#2: 185-55-15
Pro: Decent selection of LRR tires in this size (Spark/Fit/Mazda2/Fiat 500 use this size tire)
Pro: More common than 165-65-14 or 175-55-15 tires
Pro: Good fit on 6.5" wheels
Con: Slightly (0.5") taller than 165 Enasave (speedo will be slow by 2.5%)
Con: Slightly heavier than 165 Enasave

#3: 195-50-15
Pro: Same diameter as 165 Enasave
Pro: Widest most aggressive looking tire by far
Con: No LRR tires available in this size
Con: Several pounds heavier than 165 Enasaves
Con: This tire may have clearance issues on a Mirage


Best Tire Size: 185-55-15
This appears to be the best size tire for achieving my goals…
1) There are multiple long tread life LRR tires to choose from
2) This tire fits well on 6.5” wide wheels
3) Some 185's are only 3 lbs heavier than 165 Enasaves
4) 185's will fit on 6.5" wheels without clearance issues
5) They are close in diameter to 165 Enasaves (only 1/2" difference)


Best 185-55-15 Low Rolling Resistance Tire: Bridgestone Ecopia EP422 Plus
NOTE: Be sure to check my UPDATE below...there was another tire size I should have considered.

Here's why I chose this tire…
1) Bridgestone’s Ecopia line is highly rated, and the EP422 Plus is their latest LRR tire
2) It’s one of the lightest 185 tires available (~15.5 lbs vs 13 lbs for an Enasave)
3) It has a long (70,000 mile) tread life rating for a LRR tire (they last longer than that)
4) I've used Ecopias on a previous car and was happy with them
5) These tires have a similar contact patch to 165 Enasaves (see below)
6) I can buy these at Costco for not much more than people pay for no-name 14" tires

185 Ecopia 422 Plus tires have 3 very wide groves in the tread design. When you compare the width of the tread actually contacting the road, the 185 Ecopia 422 Plus is nearly identical to a 165 Enasave. The following diagram illustrates this point. This tire was updated and renamed 422 Plus from 422...with low rolling resistance as a priority. The previous version Ecopia actually had a slightly wider contact patch.



TREAD LIFE UPDATE (June 2019)
Ecopia tires have 11/32" of tread. After 70,000 miles my tires are all between 3-4/32". They are wearing roughly 1/32" every 10,000 miles. At this rate, I plan on driving them until at least 80,000 miles. I'll make the call at that point to keep going or get new tires. I will continue to update this as I put more miles on the car.


Note: Ecopia EP422 Plus tires are OEM equipment on the Nissan Leaf and Toyota Prius.


Tire Spec Chart: 165 Enasave vs 185 Ecopia

	165-65-14	185-55-15
Manufacturer	Dunlop	Bridgestone
Model	Enasave	Ecopia EP422 Plus
Type	All Season	All Season
Low Rolling Resistance	Yes	Yes
Diameter	22.4	23.0
Revolutions Per Mile	926	906
Weight	13 lbs	15.5 lbs
Tread Depth	9/32"	11/32"
Treadlife Warranty	None	70,000 miles
Speed Rating	S (112 mph)	V (149 mph)
Max Load	963 lbs	1047 lbs
Max Air Pressure	44 PSI	51 PSI
Rim Width Range	4.5 - 6.0"	5.0 - 6.5"
Country Of Origin	Thailand	Mexico

UPDATE October 2020

I replaced these tires after 93,000 miles. I went with 185-60-15 this time. Here's why...

• 185-60-15 is a much more common size than 185-55-15.
• There are a TON of tire options in this size (40+ tires in this size on TireRack.com)
• 185-60-15 tires are generally less expensive than 185-55-15s.
• A 185-60-15 is a taller tire...resulting in a 200 RPM reduction at cruising speed.
• The Bridgestone Ecopia 185-60-15s are otherwise identical to 185-55-15s.
• The taller tire fills up the wheel wells...making it look like you lowered the car

Check this thread to see 185-65-15s on a Mirage. This is probably the tallest 15" tire you can fit on these cars without rubbing. I might consider these, too.


Wheel Selection

Here are my wheel requirements for the weight, width and offset...

Weight: 13 lbs
A 14" OEM alloy wheel weighs 13 lbs…so that's the limit for wheels I'm considering.
I'm hoping to reduce the wheel weight to help offset the slightly heavier 185 tires I'll be using.

Width: 6.5"
This is the widest wheel recommended for a 185 tire.
This is the widest wheel (with 185 tire) that fits on a Mirage without clearance concerns.

Offset: 40mm
A 6.5" wheel with 40mm offset (and 185 tire) gives you adequate inner/outer fender clearance.
The rear tires will not rub under any conditions and the fronts can turn lock to lock without issue.


Best 15x6.5" Wheel: Konig Helium
The Helium is a perfect fit for my wheel requirements...
Weight ... 11.4 lbs
Width ..... 6.5"
Offset .... 40mm
Price ...... $90/each
Link to Konig Wheels





Wheel &Tire Random Observations

If you are interested in light-weight OEM wheels, see this thread: Alternative light-weight 15 inch wheels

Using a quality LRR tire is more important to fuel mileage than a few pounds of weight on the wheel. If you find a slightly heavier wheel that you really like, just make sure you match it with a good LRR tire.

Combining a heavy wheel with a non-LRR tire is a recipe for significantly reduced fuel mileage.

Most wheels are heavier than they look. Don't buy a wheel until you know how much it weighs. Some manufacturers go out of their way to hide the weight of their wheels. If you can't find a wheel's weight listed anywhere, that's a bad sign and it's probably heavier than you think.

Don't forget to consider the weight of the tire when shopping. Tires can be the same size yet vary in weight by a few pounds. LRR tires should be lighter...but not always.

Check the depth of the tread when new tire shopping. One way of cutting costs or making a tire with lower rolling resistance is to make it with LESS tread.