my friend changed on her 00 civic from 185/65/14 to 195/60/15. She's complaining that when merging on highway, that the car is very sluggish and lags in acceleration. could this be the main reason for this? It is a bone stock civic also.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mingbling96 &raquo;</TD></TR><TR><TD CLASS="quote"> It is a bone stock civic </TD></TR></TABLE>


There's your problem...

 

Did she also change out the air filter?

 

it's bone stock.. except for the rims. according to http://www.net-comber.com/tirecalc.html these tires are approximately .74" taller. Is that a significant difference?

 

it does reduce rpm(revolutions per mile) but also, its a stock civic how much does she want? check the plugs and junk for hesitation

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by prism &raquo;</TD></TR><TR><TD CLASS="quote">it does reduce rpm(revolutions per mile) but also, its a stock civic how much does she want? check the plugs and junk for hesitation </TD></TR></TABLE>

Your tach measures how many "revolutions per minute" not per mile...

Hypothetically it should help with acceleration... In other words if shes giving it gas the same as she did before the tire/rim change the engine has to put out less effort to cover the same amount of ground or she should be covering more ground with the same amount of acceleration as before. There are other things to take into consideration i/e the new tire/rim setup weighing more than before which would counteract some of the benefit you would gain from increasing the height of the tire/rim.


Modified by NineTwoSi at 3:00 PM 6/15/2005

 

[QUOTE=NineTwoSi]Your tach measures how many "revolutions per minute" not per mile...

Hypothetically it should help with acceleration... In other words if shes giving it gas the same as she did before the tire/rim change the engine has to put out less effort to cover the same amount of ground or she should be covering more ground with the same amount of acceleration as before. There are other things to take into consideration i/e the new tire/rim setup weighing more than before which would counteract some of the benefit you would gain from increasing the height of the tire/rim.


he's right bigger wheels tires means more weight and less acceleration.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NineTwoSi &raquo;</TD></TR><TR><TD CLASS="quote">Your tach measures how many "revolutions per minute" not per mile...</TD></TR></TABLE>

it does decrease rev's per mile in reference to the tire as well as the engine. it will move slightly more per revolution of the tire, decreasin the engine/tire revs to go a certain distance. this will decrease acceleration.

if you think about it, it's pretty much just changing another gear ratio

 

This is true if the rate of acceleration is less but assuming the mass weighs the same amount as before and the rate of acceleration is the same it should increase acceleration. Everyone automatically assumes the weight of everything increased because the tire/rim size did but if the weight of the new setup is the same or less it could actually benefit acceleration.

 

Gravitational pull from the moon helps too.
The beast comes out driving towards a full moon.
Tech your pants off (_|_)

 

overall diameter of tire affects acceleration. taller tires creates taller gearing so to speak.

 

yes, the car will accelerate slower with taller tires.

On a low torque car...which is what she has, benefits greatly from say a 13 inch tire. Not only less weight but better gearing.