Hello

I have a 2009 Honda Civic and i need to change my tires. I dont a lot of research because i didnt know a bout low rolling resistance thing. And i bought the continental pure contact wich has eco plus. For everything I look those tires are low rolling resistance. Normally my mpg on the was between 39-45. And right after change the tires the mpg now is between 31-35. I contact continental to see if those tires were true LRR and they sai this:

Thank you for contacting Customer Relations at Continental Tire the Americas, LLC.

The new PureContact, Eco-Plus tires, due to the full tread, will not show the same rolling resistance, or fuel economy, as the worn tires. It is over the life of the tires that you will receive the fuel savings.

As long as the tires have the appropriate size, load, and speed index, they are suitable for your vehicle.


So basically a neutral answer. So for everybody knowledge. Does the tires has to do something with this? Does the mpg will go up eventually with the wear of the tires? Do I have to reset something for the computer read the new tires or something like that.

 

New tires of any kind take 1000-3000 miles to break-in before optimal mpg is achieved.

The 8-10mpg drop you describe is likely not related entirely to the tires but some other factor like environment, terrain or driving style.

You should confirm that you have the correct size tires and that your speedo is accurate (check with smartphone gps app). A change in tire size could adversely impact mileage readings. Insure you are inflated to an elevated pressure. Running hybrid tires in the 38-40psi range is a good compromise between traction and economy.

 

Speaking of tires, can anyone recommend any all season tires from Toyo or Nitto?

 

I have been running the car in the same places and terrain, from my work to the home and back. The size is the same one before, that is the stock size fdor that car. 195/65/15. And they are at 32 psi like they suppose to.

 

Many, including myself run elevated psi due to noticeable improvements in economy. Most research into higher than recommended psi indicate improved characteristics in almost every area. The primary purpose for having the spec psi is for ride comfort and noise reduction.

Again, it is highly unlikely that tires would cause a performance hit of that magnitude.

I recommend you find a circuit where you can be certain to run 3-5 miles of constant speed flat terrain without stopping or slowing accelerating. Preferred speeds are 45, 55 and 65 mph. Establish speed, set cruise, allow to stabilize, reset your trip meter and record mileage at the end of the 3-5 miles. Repeat for 55 and 65 mph. Report back.

Also, do you ever notice just 2 bars on the battery state of charge meter?

Have you recently experienced a significant drop in ambient temperature?

Steve

 

Look I n the sidewall of your tires. I would bet the max pressure listed for the tire is going to be 44 psi. If so, try airing them up to that...or atleast 40. I would bet you experience a crisper driving experience, plus an increase in economy.

 

So the tires should have the psi recommend it on the tire or the label on the car?

 

Honda says the tires should be at the pressures on the car label. However, it is common practice to inflate somewhere between the car label and max psi listed on the tire for maximum economy at the expense of a potentially harsher ride. I find a good compromise at 38psi.

Did you have an opportunity to conduct some objective mileage experiments?

Again, do you ever see two bars on the battery state of charge meter?

 

i never notice two bars on the meter. Buyt normally it goes up and down with the assist thing . I did put a new battery the day of the tire change because when we test it it was weak. I work on pepboys so test it myself on the shop. On our systems arent anything related to low rolling resistance, thats why im searching about issues. The battery was the original scince 2009 so i know it was about to die. The psi on the tires right now is about 33-34. I have drove the car the same route scince that day about 154 miles. I live 40 minutes from my work. And mpg still the same between 30-35. I have fill up the tank one time. scince then.

 

Generally the 8 bar SoC gage on the left margin moves very slowly. The assist (white) and regen (green) scales go up and down as appropriate.

I'm asking because if you EVER see only the bottom 2 of the 8 bars on the meter lit, you are in a negative recal, which is a sign of battery deterioration. The associated forced regeneration is a mileage killer.

A negative recal is where the car stops providing assist and the SoC gauge drops to 2 bars at the rate of 1 bar per second. It force regens until one of the 11 voltage taps shows peak and then frequently does a positive recal where the car stops charging and goes to full SoC at a rate of 1 bar per second.

Have you ever noticed this behavior?