Tire question concerning MPG

[wbwanzer]

Last week I purchased four Continental Purecontact Tout 54 tires. So far so good but very limited use (less than 100 miles so far). This tire gets decent reviews on Tirerack and from users on this forum. But when I read the Tirerack reviews from users, what I'm finding is a loss of mpg anywhere from 1 to 4. And the latest reviewer says loss of 10 mpg. BUT...what I noticed was that those who lost gas milage where driving Prius or Hybrid cars. Our car is not a Prius or hybrid so not a worry for me (yet), But I'm wondering why these electric or partial electric cars are losing gas mileage while drivers of ICE cars are not mentioning this problem. And this Conti Tour 54 says 'Eco Plus technology' on the sidewall. Any idea what's going on here? Is it because these cars are heavier? Are the drivers of the ICE cars just not paying attention to their MPG? I almost didn't buy the tire until I realized that the mileage complaints were from electric/hybrids and our car is not hybrid.

I'm just curious what's going on. Thanks.

 

[Boomer]

I put those o0n my Passat about 2 years ago and did not notice any MG change. Love the tires.

 

[CapriRacer]

Last week I purchased four Continental Purecontact Tout 54 tires. So far so good but very limited use (less than 100 miles so far). This tire gets decent reviews on Tirerack and from users on this forum. But when I read the Tirerack reviews from users, what I'm finding is a loss of mpg anywhere from 1 to 4. And the latest reviewer says loss of 10 mpg. BUT...what I noticed was that those who lost gas milage where driving Prius or Hybrid cars. Our car is not a Prius or hybrid so not a worry for me (yet), But I'm wondering why these electric or partial electric cars are losing gas mileage while drivers of ICE cars are not mentioning this problem. And this Conti Tour 54 says 'Eco Plus technology' on the sidewall. Any idea what's going on here? Is it because these cars are heavier? Are the drivers of the ICE cars just not paying attention to their MPG? I almost didn't buy the tire until I realized that the mileage complaints were from electric/hybrids and our car is not hybrid.

I'm just curious what's going on. Thanks.

What is likely going on is that the OE tires on the electric/hybrids had very low rolling resistance. They do that by sacrificing tread wear and/or traction, especially wet traction. Further, worn tires have lower RR than new tires, all other things being equal. So they took 2 hits in the mpg department, but got a longer wearing tire in the bargain.

 

[IndyIan]

Last week I purchased four Continental Purecontact Tout 54 tires. So far so good but very limited use (less than 100 miles so far). This tire gets decent reviews on Tirerack and from users on this forum. But when I read the Tirerack reviews from users, what I'm finding is a loss of mpg anywhere from 1 to 4. And the latest reviewer says loss of 10 mpg. BUT...what I noticed was that those who lost gas milage where driving Prius or Hybrid cars. Our car is not a Prius or hybrid so not a worry for me (yet), But I'm wondering why these electric or partial electric cars are losing gas mileage while drivers of ICE cars are not mentioning this problem. And this Conti Tour 54 says 'Eco Plus technology' on the sidewall. Any idea what's going on here? Is it because these cars are heavier? Are the drivers of the ICE cars just not paying attention to their MPG? I almost didn't buy the tire until I realized that the mileage complaints were from electric/hybrids and our car is not hybrid.

I'm just curious what's going on. Thanks.

Losing 10% of 12mpg , 30, or 60mpg , are all are the same amount of relative increase in rolling resistance, but much different numbers in mpg lost.
If you convert it to fuel/distance, then you can see the absolute increase fuel used.

 

[dubber09]

I think there are two things going on here. First, (almost ?) any new tire will show lower mpg compared to worn out tire as it's got thread and is softer thus there is greater rolling resistance. Second, EVs and hybrids often if not always come with low rolling resistance tires to begin with.

 

[rstsco]

Continental give buyers a generous time period to drive on the tires, and if you don't like them... (I forget their policy, other than it being generous). Drive on them several tanks and see how your specific tires perform on your vehicle under your driving conditions.

Years ago I put a set of Dunlops on my S-10 4WD Blazer, having always used Michelins. Immediately I was getting 50 miles less out of each tank, so had them replaced with Michelins.

 

[TheOilWizard]

I'm skeptical new tires have a meaningful impact on MPG. Take those reviews with a couple grains of salt.

 

[IndyIan]

I'm skeptical new tires have a meaningful impact on MPG. Take those reviews with a couple grains of salt.

I just took off a set of 9 year old, very very broken in(likely all had been run low at least once) 2/32 OEM low rolling resistance AS tires. Then put on a set of 8.5/32 nearly new UHP AS, with excellent wet and dry grip and no compromises for low rolling resistance, and its pretty noticeable. Enough that I went around the car after a drive and felt each caliper to see if one is dragging!
I didn't have the car on the old tires to get a good mileage sample set, but I would think the increase in fuel usage is in the 3-4-5% range. I have had a slightly dragging drum brake before, and this felt similar.

 

[Geekhead]

If you think mpg loss is a problem add 10% more pressure to tire and I bet that will cancel it out, unless you can feel that the slightly harsher ride is unacceptable. I do this as a rule and also get more even wear and ride seems the same to me.

 

[krzyss]

1-2 mpg loss from 20, 40 or 100?

Percentage is more important than absolute number.

And what others wrote. Hybrids have low rolling resistance OEs, new tires have higher rolling resistance than new.
One more thing: hybrid drivers may pay more attention to MPG.

Krzyś

 

[oilstudent24]

Last week I purchased four Continental Purecontact Tout 54 tires. So far so good but very limited use (less than 100 miles so far). This tire gets decent reviews on Tirerack and from users on this forum. But when I read the Tirerack reviews from users, what I'm finding is a loss of mpg anywhere from 1 to 4. And the latest reviewer says loss of 10 mpg. BUT...what I noticed was that those who lost gas milage where driving Prius or Hybrid cars. Our car is not a Prius or hybrid so not a worry for me (yet), But I'm wondering why these electric or partial electric cars are losing gas mileage while drivers of ICE cars are not mentioning this problem. And this Conti Tour 54 says 'Eco Plus technology' on the sidewall. Any idea what's going on here? Is it because these cars are heavier? Are the drivers of the ICE cars just not paying attention to their MPG? I almost didn't buy the tire until I realized that the mileage complaints were from electric/hybrids and our car is not hybrid.

I'm just curious what's going on. Thanks.

I bought those same tires a few weeks ago and show slightly less on the mpg readout. I always figured that the old tires had less tread showing more revolutions ( miles traveled per tank) and were lighter to boot. Most people seem to always lose mpg with new tires it seems. I also assume the tires had some compound that had to wear off for a short time when the tires were new.

 

[JHZR2]

Thank you for posting this!

I have seen about a 6 mpg drop going from Michelin energy saver to continental tires in my accord hybrid.

I posted about it here:

Thread 'Michelin Energy Saver A/S Replacements'

Nov 24, 2024

My Accord Hybrid is at 90k miles. There’s about 4/32 still on the OE Energy Saver tires that came on the car.

I had talked about this in 2022:

And now the time has come. The plan was to just get the same…

But it looks to me that these tires have been discontinued. I can’t 100% determine that. Regardless, they’ve become VERY expensive. $269/tire for not a very aggressive or large size.

I’m very concerned about losing MPGs.

I have winter tires that I haven’t used in probably six years now, but...

• JHZR2
• Replies: 72
• Forum: Tires & Wheels

• 

Some folks told me it was the winter fuel and a range of other excuses. Yet in the depths of winter when I swapped to different snow tires, my mpgs returned.

Something about the continental designs make them NOT LRR.

 

[wbwanzer]

Thank you for posting this!

I have seen about a 6 mpg drop going from Michelin energy saver to continental tires in my accord hybrid.

I posted about it here:

Thread 'Michelin Energy Saver A/S Replacements'

Nov 24, 2024

My Accord Hybrid is at 90k miles. There’s about 4/32 still on the OE Energy Saver tires that came on the car.

I had talked about this in 2022:

And now the time has come. The plan was to just get the same…

But it looks to me that these tires have been discontinued. I can’t 100% determine that. Regardless, they’ve become VERY expensive. $269/tire for not a very aggressive or large size.

I’m very concerned about losing MPGs.

I have winter tires that I haven’t used in probably six years now, but...

• JHZR2
• Replies: 72
• Forum: Tires & Wheels

• 

Some folks told me it was the winter fuel and a range of other excuses. Yet in the depths of winter when I swapped to different snow tires, my mpgs returned.

Something about the continental designs make them NOT LRR.

Thanks. Very interesting.

 

[CapriRacer]

Maybe it's time for me to talk about rolling resistance of tires. Usually I would point to my webpage on the subject, but I haven't started converting it yet to the new format. So you'll just have to put up with this brief and largely undocumented look-see.

Tread rubber compounds have a HUGE! effect on a tire's rolling resistance. It's not the hardness of the rubber. It the internal friction - something called hysteresis.

There's a technology triangle involving treadwear, traction (especially wet traction), and rolling resistance. To improve one area, one or both of the others has to be sacrificed.

Further, the amount of tread rubber also has an effect. More rubber = worse RR.

And inflation pressure has an effect as it controls how much the tread is deflected. More pressure = less RR.
I captured a pair of charts from Smithers, a respected tire testing company, that shows that the best new tire RR was as small as 60% of the worst in the same size. Put another way, if we compare a large group of tires that are the same size but different types - all season, all terrain, LRR, etc., the worst tire is almost twice as bad.

How much effect this has on fuel economy varies widely depending on the vehicle and how it used. I've seen documents that say 10% is a reasonable estimate for most cases, but again, certain circumstances can make this higher or lower.

Because of this, car manufacturers specify LRR tires for their new cars. That's the reason OE tires have such a bad reputation for wear and traction.

 

[rstsco]

Because of this, car manufacturers specify LRR tires for their new cars. That's the reason OE tires have such a bad reputation for wear and traction.

CAFE strikes again!

 

[MParr]

The last paragraph of what @CapriRacer said is spot on.
I never replace OE tires with LRR or Eco-friendly tires.

 

[barryh]

In the EU and UK tyres are labelled with an energy class A-G. In trying to understand the practical difference this made I discovered that each class has a numerical coefficient of rolling resistance which showed the worst class G having 86% or near double the coefficient of class A. I produced a little table which showed the difference between the classes and what that translated to in terms of typical impact on MPG. So a class B tyre consumes 0.9% more fuel and so on to the worst tyre consuming 7.8 % more fuel than the best.

In practice that saving of 7.8% is not realisable because you'd be very hard put to find a class G tyre to buy. Almost all normal car tyres fall into the A to E bands which still allows a good saving of 4.6%