Were my tires throwing off my fuel logs? Help

[RandomFact314]

Hey I was looking at a profile on here where someone said that the tires on their car or whatever it was were 6% bigger then the stock so he calculated the 6% into the fuel logs for 6% addition to the miles driven. The tires I had on for a while are 10% bigger then the stock/ones I have on now. Was I suppose to add in that 10%

[Christ]

Yes. :P You screwed up.

What you actually have to do is calculate the difference in rolling circumference, not diameter. You add in the % difference of the circumference, since you've gone that much further.

[RandomFact314]

Originally Posted by Christ

Yes. :P You screwed up.

What you actually have to do is calculate the difference in rolling circumference, not diameter. You add in the % difference of the circumference, since you've gone that much further.

So can you tell me what I need to do to my fuel logs for when I had those tires on? add or subtract from them and by how much?

[Christ]

If your tires were 10% bigger circ, you add 10% to the miles driven.

[RandomFact314]

Originally Posted by Christ

If your tires were 10% bigger circ, you add 10% to the miles driven.

So that chart is correct? I DO use 10% in this situation?
If so then for ex. if I drove 300 miles I should take 10% from 300 and add it to the 300, that being 330 and put 330 in the place of the 300 right?

[Christ]

[RandomFact314]

Originally Posted by Christ

are you 100% sure before I go and modify 9 of my fuel logs 4ever?

[Christ]

Originally Posted by RandomFact314

are you 100% sure before I go and modify 9 of my fuel logs 4ever?

Do I have to support my statements with logic?

[RandomFact314]

Originally Posted by Christ

Do I have to support my statements with logic?

No, besides I cant argue with writing down a less-good FE than it was

[Christ]

It'll show better mileage... more distance on the same fuel.