I got 195/50/15 now. If I go with 195/55/15, the tires will be 10% taller.

Will that mean my gear ratios will be like 10% taller. Does that mean I will get better MPG?

I know about the speedo error, and I'm ok with that.

What do you think? Will I get better MPG assuming driving style remains the same?

 

You're effectively changing the final drive ratio by doing that, not the individual gear ratios.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dpaton &raquo;</TD></TR><TR><TD CLASS="quote">You're effectively changing the final drive ratio by doing that, not the individual gear ratios.</TD></TR></TABLE>

Yep, and likely get worse gas milage.

Your car was designed to get peak gas mileage at it's factory tire size.

 

Many said if I go with a shorter profile tire, I was suppose to be quicker off the line. Why can't the same thing be said for taller tires?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by YipMan_Style &raquo;</TD></TR><TR><TD CLASS="quote">Many said if I go with a shorter profile tire, I was suppose to be quicker off the line. Why can't the same thing be said for taller tires?</TD></TR></TABLE>
They weigh more

 

when you change wheels and tires you mess with fuel milage, speed, gear ratio, weight, and traction

 

technically if you raised the tire size by enough you would be effectively lowering your rpms at all speeds

so if you're doing a lot of freeway driving then you could be increasing mpg because of the lower rpms at freeway speeds/long distance driving.

i don't know how much you need to change to notice a difference though.

 

Well, too much bigger and it will be harder on his valvetrain, driveline, and transmission, thus creating more work for your engine.

Closest to stock size will net you good gas mileage.

 

valvetrain driveline and transmisson


#1 how can it be bad for his vavle train do know what a valvetrain is?

#2 driveline is slang for engine and tranmisson

#3 see #2 <TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ek forever guy &raquo;</TD></TR><TR><TD CLASS="quote">Well, too much bigger and it will be harder on his valvetrain, driveline, and transmission, thus creating more work for your engine.

Closest to stock size will net you good gas mileage.</TD></TR></TABLE>

 

wow, you guys all suck, giving him such shitty, one sided info.
Changing between those two sizes of tires, you shouldn't notice any difference in mileage. If nothing else, the larger tire will travel more distance over time the odometer clocks a mile. Getting slightly less in miles per gallon, while clocking less distance than you have gone, it balances out. There's no point in doing it, unless your tires are bad.
****** kids.

 

look i work in a tire shop if you put them tires next to each other your not even going to see a difference its such a small difference its not going to do anything.we change sizes all the time.its not a big deal

 

if you know you gear ratios I have a excel program that is a speed calculator that includes tires size and rpm that will graph and tell you your top speed let me know if your interested

Here is is http://www.k20a.org/upload/GearRatioCalculator.XLT
You must use the overall diameter of rim and tire in inches,,,,

 

Fatboy Transmission Gear Ratio Calculator
Same basic thing, just easier to use.