Sorry guys but i need a quick answer here as i have found a great deal on lowering springs, but they are for RWD and my 08 is250 is AWD. Whats the difference as to why i cannot use the springs meant for RWD?

Thanks in advance!

 

I assume you know the brand? Go to their site and see if they offer the springs for AWD and see for yourself what the difference is. I expect there is some due to the front differential and F/R weight balance being different between RWD and AWD, but I don't know that.

 

I have tried to go on their website but it does not state what the differences are, just different part numbers. But for example some brands have the same part number for both AWD and RWD, meanwhile others have different part numbers. Just trying to figure out if there really is a difference, as i don't want to find out the hard way having everything apart.

 

Okay. Looking at BC Racing Coil Overs, they have a different strut for IS250 AWD vs RWD

AWD
https://bcracingcoilovers.com/collec...cing-coilovers
Front Spring Rate = 10k Rear Spring Rate = 8k

RWD
https://bcracingcoilovers.com/collec...lovers-br-type
Front Spring Rate = 12k Rear Spring Rate = 10k

That would lead me to believe that the spring rates ARE different between AWD and RWD and that makes some since due to the F/R weight balance

 

From my understanding the springs are the same. The shocks on the other hand are different. So RWD springs will fit AWD. Coilovers are different because they include the shocks as well.

 

Perhaps go to t o y o d i y com and enter your vehicle. It will show different PN's for RWD vs AWD. Mind you different damping rates internal to the shock would create different PN's while the physical shock carries the same dimensions externally. So it may not tell you all you need to know. But compare the two....

It seems some links offer strange behavior...

 

I think H&Rs are the same. awd vs rwd.

 

From their website they have different part numbers, -1 and -3, but doesn't say what the difference is exactly. I'm kinda willing to try it out and find out for myself.
Thanks guys!

 

I think that the Box numbers are differnet. Part number on the springs themselves is the same.

 

AWD has a slightly longer front strut than RWD, by maybe 1/2 inch. So if you put a set of RWD spring on a AWD, your front will sit higher than they were designed for. Some people are fine with that, but if you have sharp eyes, it will drive you crazy.

 

this is exactly right. I got the H&R AWD springs on my awd because the springs lower the car something like 1.2" front and 1.4" rear. this allows the car to sit evenly. if you put rwd springs on an awd IS, they will fit, but the car would sit unevenly. so you need staggered est. drop front/rear (lower slightly in the rear)

 

if I have a staggered wheel set up on my 2015 is250 AWD. I found a good set of super down rsr springs but there from a RWD model. will this set up look weird? will it work?

 

Super late. Have an 09, I emailed h&r, they stated the springs are the same for rwd, and AWD. Only part number difference for catalog reasons. Part numbers on springs are identical. 29122va for front, 29122ha for rear.