Goodyear Assurance Comfortreads = Loss of 2 MPG

[Fordiesel69]

Vehicle: 99' Crown Victoria Police, 16" Rims, 3.55 axle ratio.

P225/60/16

I have owned these tires for about 1 year and 6500 miles. I have a measured reduction in fuel economy with these tires. At 44PSI I get high 19MPG highway. On my old Goodyear Viva 2's which are basically a walmart tire, I was always getting high 22 MPG or more. Those tires had 3/32 tread left and were pretty much shot, whereas these new assurance have 10/32 now.

So why is there this much loss of fuel economy?

I am not imagining it. I can put my snow tires on and still get good mileage (21/22MPG) but I don't want to wear them out.

 

[sciphi]

The older tires were slightly over-reporting mileage traveled, so it looked like they were better than they were. The old tires were roughly 1/2" diameter smaller than the new, full-tread tires. The difference is 7/32" in radius (tread depth), which works out to 14/32" difference in diameter (since diameter = 2*radius), or roughly 1/2". The new tires also likely squirm a little more, which wastes energy. The older tires didn't suffer from tread squirm since they had little tread remaining. So, a drop in fuel economy with new tires is to be expected.

I've also read that Comforttreads are indeed comfy, but sacrifice MPG to do so.

 

[Bgallagher]

I didnt notice a drop in MPG but those tires were terrible on my Malibu. they wore quick, were loud and the winter traction was scary. I was good about rotating and balancing them but nothing helped. I switched to Cooper lifeliners and it made a big difference. Sorry to hear about your MPG loss but as mentioned above, you sacrifice one for the other (hopefully your experience will be better then what I had.)

 

[AuthorEditor]

Wow, I'm surprised the Crown Vic Police gets that much lower mileage than the civilian versions. I have measured my highway mileage many times on a civilian Vic and my current Grand Marquis at 25-26 mpg (65-70 mph).

 

[Fordiesel69]

The fact you metion that they are comfy but sacrifice fuel MPG seems to be true as some owners of hondas reported the same when I was doing my reaearch.

So is there brands or styles of tires that would get good mileage?

These truly are the quietest, and smoothest riding tire I have owned. But I am having trouble accepting the fuel economy.

 

[Fordiesel69]

Originally Posted By: AuthorEditor
Wow, I'm surprised the Crown Vic Police gets that much lower mileage than the civilian versions. I have measured my highway mileage many times on a civilian Vic and my current Grand Marquis at 25-26 mpg (65-70 mph).


I run 72-74mph which doesn't help. But the 3.55 axle, higher rear ride height, dual exhaust, and different pcm programming does play a role in the fuel milage reduction over a civilian.

But my reduction is definatly the tires. I ruled that part out.

 

[cbear]

I know I lost 1-2 MPG when I ran GY Triple Treads, a very similiar tire. My TTs had more traction than any other tire I've run.

 

[Kuato]

The new tires are same size as previous, right? I had a Mercury GM, stock tires got 25 on the highway. Could not pass up a sale on some new tires that were slightly taller, and mileage went to 17-18highway.

 

[andersd]

On my 02 Grand Marquis switched out Goodyear Integrity's at half tread for the T rated comfortreads around 50K ago due to bad cupping from previous owner. Mileage has been mostly unchanged at an average of 23 mpg on 75+ straight freeway driving. Have always kept the recomnded 35 lbs air pressure year around. Traction is better than the previous tires and does have a quite ride, plus should easily make the 80k suggested life.

 

[Rand]

the stock tire size is aprox 26.6"

you can expect to lose 2% or so just from the tread depth difference.

also your comfort treads maybe on the large size and viva2 may have been a small size.

225/60r16 there is still a variance in small size between models and brands.

also that tire is not an oem or fuel saver type tire.

if you are getting 19mpg now thats very possible the best you will get until they wear down and start over-reporting distance traveled and you pick up another 1mpg

you might also pick up a mpg from less tread squirm

I replaced the oem yokohama g95a's with same size kumho 4x and lost some MPG too

went from 26.5 average to 22.5 average.. but its also colder now. so who knows exactly how much I lost.. and what is seasonal variation.

 

[bourne]

I have noticed 0 loss in mpg on these tires. in fact, I got my best hwy mpg (32mpg) with these tires in my Acura. Very happy with the ride. I run them @ 34 psi front 33 psi rear.

 

[The Critic]

Originally Posted By: bourne
I have noticed 0 loss in mpg on these tires. in fact, I got my best hwy mpg (32mpg) with these tires in my Acura. Very happy with the ride. I run them @ 34 psi front 33 psi rear.


Put on a set of Fuelmax tires and get back to us.

 

[Hokiefyd]

Originally Posted By: Fordiesel69
So why is there this much loss of fuel economy?


The Viva 2 tires you had on the car are rather similar to the Integrity. They are based on the Regatta/Integrity tire as I understand, and will likely provide good rolling resistance.

By comparison, the ComforTred is not a tire designed to have low rolling resistance. It's a soft tire that is also intended to provide long wear. None of these attributes correlate with good rolling resistance. In combination with the differences in tread depth between old and new tires, the ComforTreds, in theory, should never provide the fuel economy of an Integrity/Viva type tire.

 

[CharBaby]

Originally Posted By: andersd
On my 02 Grand Marquis switched out Goodyear Integrity's at half tread for the T rated comfortreads around 50K ago due to bad cupping from previous owner. Mileage has been mostly unchanged at an average of 23 mpg on 75+ straight freeway driving. Have always kept the recomnded 35 lbs air pressure year around. Traction is better than the previous tires and does have a quite ride, plus should easily make the 80k suggested life.



I change the OE Integrity's on my wifes Lexus with 1st gen G/Y ACTs(NonTouring) at 59K miles and I haven't seen any difference in MPG either. But, I have read many reviews from those who have lost MPG.

I like the ACT's much better than the Integ's, just for the traction alone!

 

[eljefino]

Originally Posted By: Hokiefyd
It's a soft tire that is also intended to provide long wear. None of these attributes correlate with good rolling resistance.


I'm surprised the long treadwear doesn't equal good fuel economy. I'd expect both with the tradeoff being mediocre grip.

Looking at the tread pattern with its barely cut center rib I'd expect it to roll kind of okay. Goes to show you can't always get what you expect from looks alone.

 

[CapriRacer]

OK time again for my lecture on rolling resistance:

There is a technology triangle involving treadwear, traction (especially wet traction) and rolling resistance. In order to get an improvement in one area, one or more of the other areas has to be sacrificed.

There is also a HUGE range of RR values even for the same size - (about 60% difference best to worse). So changing tires could result in quite dramatic differences in fuel economy depending on what you took off and what you put on.

There is also a difference between wornout tires and new tires - all other things being equal.

Needless to say, this issue is chock full of complication making it difficult to sort it all out.

 

[bourne]

Originally Posted By: The Critic
Originally Posted By: bourne
I have noticed 0 loss in mpg on these tires. in fact, I got my best hwy mpg (32mpg) with these tires in my Acura. Very happy with the ride. I run them @ 34 psi front 33 psi rear.


Put on a set of Fuelmax tires and get back to us.

Lol , even though I work for Goodyear, FuelMax arent necessarily the tires that I like to recommend on cars.They are usually my 3rd/4th option. Their SUV version ( Assurance Fuelmax CS ) is awesome. Ive got customers telling me they get about 80~100 more mpg/tank. These are the folks that make the same trip at the same time in the same car with the same person to the same place every year. So conditions are fairly consistent.

 

[HTSS_TR]

Originally Posted By: bourne
Lol , even though I work for Goodyear, FuelMax arent necessarily the tires that I like to recommend on cars.They are usually my 3rd/4th option. Their SUV version ( Assurance Fuelmax CS ) is awesome. Ive got customers telling me they get about 80~100 more mpg/tank. These are the folks that make the same trip at the same time in the same car with the same person to the same place every year. So conditions are fairly consistent.


The tire alone can get 80~100 more miles per tank ? 80~100 miles from normally 400-500 miles is about 20%. Is it possible ?

 

[surfstar]

Originally Posted By: HTSS_TR
Originally Posted By: bourne
Lol , even though I work for Goodyear, FuelMax arent necessarily the tires that I like to recommend on cars.They are usually my 3rd/4th option. Their SUV version ( Assurance Fuelmax CS ) is awesome. Ive got customers telling me they get about 80~100 more mpg/tank. These are the folks that make the same trip at the same time in the same car with the same person to the same place every year. So conditions are fairly consistent.


The tire alone can get 80~100 more miles per tank ? 80~100 miles from normally 400-500 miles is about 20%. Is it possible ?


No, no, no. He said M-P-G / tank. Much better than miles.

 

[George Bynum]

Originally Posted By: Rand
the stock tire size is aprox 26.6"

you can expect to lose 2% or so just from the tread depth difference.
Capri didn't address it here, but I am of the opinion that the revolutions per mile are relatively constant as the tire wears ... the steel belt is the PRIMARY determining factor if reasonably loaded. VERY lightly loaded ... tire (including rubber) circumference. Normally loaded, belt circumference. Capri, another lesson please?