Cant seem to find an answer to my question. I posted this in my.is forum as well.
I just picked up an 08 is350 (rwd) and wanted to lower it. Based on the numbers alone for example, eibach pro kit states that the drop on the 250 is 1.4f and 1.0r. For the 350 its 1.0f and 0.8r. My questions are 1. What is the difference between the 250 and 350 that would make them need separate springs. 2. If I put 250 springs on my 350 would it drop it 1.4 and 1. or would it be lower or higher? 3. Any other popular IS forums?

Any help is appreciated. Id like to put springs on ASAP.

 

Hmm interesting because I sold my tein s-tech springs to my friend recently and she drives a 250 while I drive a 350. There seems to be no problem on the installation at all. Maybe you should try calling eibach, but as far as I know there suspension are the same unless I guess you have the xpkg.

 

they should be the same

 

I checked out a 250 today and the wheel gap is identical to a 350. So i think ill go with the 250 springs. I just wanted to make sure it wasnt going to slam it or leave it too high.

But honestly im disappointing in these forums. Seems like a simple question that tons of people could answer. MYg37 would have had this answered in minutes.

 

Google + Searchy is key. 100's of posts here are doubles of what other people ask. remember this car has been out since '06. Its now '10. You said it your self
IS 250 is 1.4f and 1.0r . For the IS 350 its 1.0f and 0.8r. Its a simple as calculating the 250 and 350s stock height and subtracting the springs offset from them. If you really wanted to know im sure you could have figured it out yourself. just my two pennies...

 

Google isn't necessarily the key. Plenty of CL members have both Eibach 350 springs and Eibach 250 springs on IS350 cars and in both cases the cars are lowered by the advertised amount for the given springs. Specifically CL searches will be more useful.

 

Agreed^^^..CL searches would have provided you with your answer in a couple of minutes..There have been many threads on these spring combos..FYI IS250 rwd and IS350 rwd are the same..IS250 awd slightly different but you can still use rwd springs on them..there are also the sport package springs which come on the IS250 rwd or IS350 rwd which are also slightly shorter than regular rwd springs..Regardless of what stock springs you have the eibach 250 or 350 should work on your IS...I would go with eibach 250 for your car if you want a lower drop..

 

I checked out the forums for a couple days and couldnt find a clear answer, hence why i posted a new bulletin. Can you point me in the direction to where you found these posts?

 

Since you have a IS350, so you can use either Eibach 250 or 350 springs. The actual drop will be very close to the amount advertised by Eibach.

I assume you are using Search this Forum at the top right of the page.

 

Thanks! Thats the kind of answer I was looking for.