Tire size change, Need answer quick!!!!

[Gone2]

I currently have 175/70r13's on my Sentra. I am getting 39ish to the gallon doing 63 miles one way to work everyday. My curiosity is if I upsize to a 195/75r14, as I have a chance to purchase a whole set tomorrow, will it help or hurt my gas mileage. My mind says it will help, as the revolutions per mile will drop, but all the forums I read on it says it will hurt mileage. Some one help me figure this out

[BHarvey]

Shouldn't hurt on the highway, and might not hurt in town. Your revs should be lower, if the same tire is to be used on either wheel size.

[Gone2]

What do you mean by same tire size on either wheel. I will be about a half an inch wider but 2 inches taller. I will set up higher that may effect airflow, so I am trying to factor that into the process.

[some_other_dave]

It should help your highway MPGs, after you take into account that you are traveling farther than your odometer shows. (Old tires ~= 22.6" diameter, new tires ~= 25.5" diameter.) Each mile on the odometer will be about 1.13 miles actual distance.

Effects in the city probably depend more on your driving style than on the exact tire/wheel diameter.

Expect the car to feel less peppy when accelerating at a given speed.

-soD

[Gone2]

Then consensus says get the tires and report back with how the highway/city mileage changes. Will do. Any more input before I buy them tomorrow would be greatly appreciated.

[Ladogaboy]

Those tires/rims are quite a bit larger. You might want to make sure they actually fit, first.

[SentraSE-R]

Tall tire test. Message 56 in the thread, on page 6, summarizes the final testing. YMMV.

[oil pan 4]

Might as well try it out, we have too many people that are all talk.

Taller tires helped my truck, it didn't seem to effect city mpg but helped high way mpg.

It would be nice to have some good numbers for a small car being driven mostly highway on bigger tires.
With new tires it takes a few thousand miles to break them in so for a while MPG numbers will be lower.

[mcrews]

wow.
would just searching get you the results.
we've beaten this horse dead a couple of times.
How much hwy driving?
if over say 50% you will see an improvement.
as mentioned it will be a little slower off the line...but hey, it's not a race!
Frank lee's truck didnot benefit from taller tires.
but most cars do......again if you try to make up the slower start by driving 'faster' you'll lose any gain.

[Gone2]

95% highway driving, and now I see that there is a fair amount of information about it. I didn't have too much time to research it yesterday and the seller wants them gone today by noon. Thanks for the information and I'll post my results soon.