R-Spec MPG

[palloverspec]

Hey guys. I replaced my contis with Goodyear Eagles 245/45/19. Noticed I am getting better gas milage based on the computer. I will do more of a scientific test. Seems like with the increase tire width, I should get lower gas milage. I am averging about 23.7 mph with combined city and highway.

Has anyone experienced this with larger size tires?

 

[Mark_888]

Hey guys. I replaced my contis with Goodyear Eagles 245/45/19. Noticed I am getting better gas milage based on the computer. I will do more of a scientific test. Seems like with the increase tire width, I should get lower gas milage. I am averging about 23.7 mph with combined city and highway.

Has anyone experienced this with larger size tires?

Some tires have less rolling resistance than others, and could offset the fact that they are wider.

 

[landtuna]

Has anyone experienced this with larger size tires?

If the Goodyear's circumference is greater than the Conti's your speedo is now "slower" than stock so your MPG readings will be better.

 

[Billfz1]

I have a long commute to work, 50 mi one-way, but fortunately mostly back roads. My car rarely sees a day that it doesn't hit at least 100 and the mileage is pretty good for such foolishness. After at least 20 miles to get a decent average I average 19-22 even with a heavy foot. In town driving is where it takes the biggest hit, mine showing around 18-20. My wife took the car on a long trip from central California to Utah drove all on cruise control when possible and got 29-29.8 on the trip running regular gas. This all on the guage, but mine was pretty close though still optimistic at about 1-2% high. This is good mileage for a car with this kind of power. My R spec is a 2013 and is just past first service at around 10K miles. Cheers, Get the car you will love it.
Bill

 

[427435]

If the Goodyear's circumference is greater than the Conti's your speedo is now "slower" than stock so your MPG readings will be better.

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If the new tire has a greater circumferential, both the speedometer and mpg readout will be lower than actual--------------not better.

 

[landtuna]

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If the new tire has a greater circumferential, both the speedometer and mpg readout will be lower than actual--------------not better.

You're correct. My bad. Teaches me answering posts should be done while NOT trying to multi-task.

 

[dareckibmw]

I never physically measured the consumption - expected the car calculation to be accurate.

In my case the car calculation is not accurate. It wasn't that bad, only "off" by 2.42%

As you can see in the picture, the computer says 16.9 mpg however, after driving 268.1 miles, I've filled the tank 16.19 gal. this gives me an average of 16.55 mpg.

As I stated before, I usually get 17-18 mpg...but this time I let the Wife take it around the block a few times

 

[kf4zra]

I use an app called "a car" to track my mileage from what the odometer says and what the pump says. The computer is off between 1-2mpg. It shows better than the actual fuel economy.

over the last 3 months I filled up 7 times (I am on the road driving other people's cars for work) and averaged over the tanks from as low as 19.5 to as high as 23.9

my commute is 22 miles each way, and 80% of it is at speeds from 55-65mph. I drive like grandma, til i decide that the carbon needs to be blown out, or when someone is dragging through a toll booth. I accelerate smoothly, and coast to a stop. I redline it only a few times a tank.

My mileage was about 2 mpg lower before i switched to ethanol-free gas.
i never saw a difference between 87 and 91 octane on the e10 gas.
The E0 that I run now is 89.

I tried the air pressure in the tires a couple pounds higher, but the ride became stiffer.

driving habits make a huge difference, if you dont want to change your driving habits, running ethanol free gas will help your mileage.

www.pure-gas.org will show you where the stations are that carry it near you