noob

[markz]

got 97 1.9 td jetta 5 spd. best mileage 44 mpg. what do you all think about swapping 195 60 14 tires for 195 70 14 (1.5ish taller)tires then moderately lowering?

[Frank Lee]

I'd try it. Maybe if you're not really committed to the idea or sure of it's success, you could score a pair or four cheap junkyard tires for a trial run.

[endurance]

Double check with a dealer or tire shop that has a compatibility book that they'll clear the wheel wells first. You should be fine, but some cars really don't leave much room for change.

[markz]

was thinking about trying, they would increase the radius of tire by 3/4" tops but cover about 7% more ground thanstock. i can start out at idle in 2 nd gear with this thing

[IsaacCarlson]

I have larger tires on my truck and they give an increase of about 5% + or-.
I am either covering more ground at the same revs or turning fewer revs at any given speed. I guess it depends on how I want to look at it. Either way it is a plus. I will continue to run larger tires. I have been getting about 28 mpg in the truck by the odometer, but the real mileage is about 30!
Go for it!

[IsaacCarlson]

BTW...you would be getting about 47 mpg.

[markz]

just wanted to see what you guys thought or experienced... made sense in my mind...simple math & physics

[cfg83]

markz -

I went here and repeated your calculations. It would be a 6.6% gain with the new tires. If the odometer said 60 MPH, you'd actually be going 64 MPH. The wheels would raise the car up by 0.75". I agree that this is a cool mod.

Just to ask my standard-issue questions. Would the new tires fit on the same wheels and would the new tires fit in the wheel-well? Also, what is the before/after weight difference of the tires?

CarloSW2

[euromodder]

Welcome to ecomodder.

Originally Posted by markz

got 97 1.9 td jetta 5 spd. best mileage 44 mpg.

44mpg as a best value isn't spectacular in that car with a TD or TDi engine - which one do you have ?

I've driven both engines to around 50mpg in similarly sized cars, and I wasn't really trying hard back then. No mods at all.
There were no dedicated low rolling resistance tyres then, either.

I'd suggest to start with changing your driving style and/or technically checking out the car before you start doing serious modifications to it.

[markz]

carlos... the tires have same section width so to my understanding should be good for a go, wieght difference maybe a pound per tire?
euro... mpg # calculated with us gallon which is 3.78l, i think imperial is 4.18? also done on my regular 360km route averaging 100km/hr, has a lot of long 6-8% grades. on a different route i took last summer it seemed to do better.
thanks for the welcome guys