4 year report

[teddy]

Great post!

Originally Posted by maximapitko

I've replaced the oem tires at 55k with 195/60/15 pirellis (slightly bigger) - instantly I lost 2mpg but gained a lot better ride.

I suspect this isn't accurate. When you switch tire sizes it means the speedometer/odometer loses a certain % accuracy. Say it's 2%, when you drive 100km the odometer might only read that you'd traveled 98km. This will obviously affect your mileage calculations. I believe it can be fixed by having this stuff calibrated.

Of course you are probably losing some economy by having a larger tire, but not by that much.

[brg88tx]

Originally Posted by teddy

Great post!



I suspect this isn't accurate. When you switch tire sizes it means the speedometer/odometer loses a certain % accuracy. Say it's 2%, when you drive 100km the odometer might only read that you'd traveled 98km. This will obviously affect your mileage calculations. I believe it can be fixed by having this stuff calibrated.

Of course you are probably losing some economy by having a larger tire, but not by that much.

yep, i have 195/60r15 tires also and they are 1.98% too large, so your odometer is reading 1.98% too few miles. when i calculate my mpg i take the total miles driven and multiply it by 1.0198 to come up with the actual miles driven.

i suspect this is where your 2% perceived loss in mpg comes from.

[Happy Little Pony]

Originally Posted by brg88tx

yep, i have 195/60r15 tires also and they are 1.98% too large, so your odometer is reading 1.98% too few miles. when i calculate my mpg i take the total miles driven and multiply it by 1.0198 to come up with the actual miles driven.

i suspect this is where your 2% perceived loss in mpg comes from.

It's really remarkable. I just put on new tires the day before yesterday: 195/60r15! And I was just using my junior high level geometry skills to try to estimate how far off my odometer will be. I came up with 1.68 percent, so I'm happy to see that I'm at least in the ballpark. I figure I can use a GPS on my next long drive and get a better idea.