Significant reduction in MPG

I wonder if the tire diameter is different than the original tires? That could affect what the system thinks it is getting for mpg.

 

<div class='quotetop'>QUOTE(Nickp001 @ May 31 2006, 09:14 AM) [snapback]263356[/snapback]</div>

There is a whole thing in the manual about changing tires. Anything besides the manufactuerd tires for the car need to be entered into the system. I'm pretty sure you have to account for the dimensions of the tire, because even tiny insignificant changes over hundreds of miles greatly affects the output on the screen. I wish I could be less vague, but look in your manual and you will find it.

 

new tire breakin is a big MPG killer. i wonder if they're also not LRR (low rolling resistance) tires- that would have an effect too. there are plenty of others here who have changed to the comfortreads- if you do a quick search i'm sure you'll find plenty of opinions.

 

There have been a number of posts on the subject of tire break in. I think you need to be prepared to take a hit. We all feel for you. We will each have a turn at this and it will be difficult. I am going to do mine in winter if possible so I can blame the weather. The spring is a bad time, I look forward to the rising MPG and get depressed every time the weather takes a turn for the worse.

 

Did you solve this

 

New tires will lower the mpg, which is in line with my previous experience. The mpg of bare tires is the best. Of course, it will affect the braking distance and even the safety performance. You can try to adjust the toe of the front wheel. If the 0 toe feels stable while driving, keep it. This is the best fuel economy performance. The toe of the rear wheel is tested. It will have an impact on the driving resistance. You can use a tape measure to measure the front and rear track of the tire. The track difference is the toe, preferably 0 or slightly negative, because the rear wheel inclination is generally a small negative value, and the toe adjustment of the rear wheel can be used The method of adding spacers is realized.

 

That may be your experience, but it does not follow that all new tires will reduce MPG. There are many factors to do with the rolling resistance that comes into play.

My experience is when mounting the same make and model of tire, fuel economy is unchanged.

If you go from one make and model to another, all bets are off.

 

This thread was 15 years old. Chances are that you won't get a response from the OP.

Goodyear ComforTred tires are not a low rolling resistance tire. Goodyear's LRR tires are Assurance FuelMax.

We have been averaging 52.X mpg on the previous set of 15 inch FuelMax tires. We just put on a new to us set of 16 inch wheels with 16 inch versions of the Assurance FuelMax tires. The rims are one pound heavier than the stock alloys. Still early to tell what mpg will be like on this set of tires.

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I want to explain my point of view. The new tires of the same model are different from the old ones, and the resistance of the new tires will increase a little bit. As the mileage increases, they will get better after running-in. This is my point of view.
when the vehicle is running, even if it is driving in a straight line, the friction between the tires and the ground is not completely rolling. Due to the existence of the inclination angle and the toe (other angles are not considered when driving in a straight line), the friction will have a tendency to push, this tendency Sometimes it is to make up for the gap of the suspension system. The gap cannot be completely eliminated (in any case, the cost and driving feel of the vehicle are all compromised and compromised in the design of the vehicle). This gap will cause unstable driving conditions. Generally, driving vehicles are designed with front wheels toe in, and the rear wheels are slightly negative inclination to increase cornering grip. The existence of these angles causes the wheels to have a little sliding friction with the road surface when driving, causing the tires to hang inward or Outward or rotating force to reduce unstable factors. The existence of these angles will cause some sliding friction on the tires. Therefore, when the gap between the suspension rubber sleeves, ball joints and other movable components is small, it is recommended to adjust the toe and camber angle to 0 to reduce slippage. The generation of resistance (provided that it does not affect stability). The surface of the new tire pattern is relatively rough and deep, but also relatively soft. The same tire pressure deformation will be larger. The contraction and recovery will continue to require energy. The roughness will cause the sliding friction resistance to be greater. After a certain period of running-in, the resistance will decrease. No vehicle can completely avoid sliding friction. All you have to do is to minimize it and maintain stability as a compromise.
What I want to say is that sometimes the toe, inclination angle and tire pressure will have a greater impact than the type of tire. If all is good, changing to a low-resistance tire will have an effect.

 

I’m sorry I just noticed that this is a post 15 years ago, I think it may have some effect on others, and the problem remains the same.

 

LOL
New Member, Nickp001 was last seen: May 17, 2009