Hey guys,

I'm replacing my lower control arm bushing but there seems to be 3 available options on sewell lexus. Do any of you know what the offset actually does and which one I should purchase?
2007 Lexus IS250 RWD

 

Offset changes caster to adjust the alignment. It depends on which one you have now and whether or not you want to adjust the caster. Chances are you will want 0 offset, but I can't say that definitively.

Jeff

 

Thank you for the quick reply. The car is not modified at all. I'll order the 0 offset and hope for the best. Thanks again!

 

Would there be any benefit to ordering one of the more offset bushings if the car has the "0" offset bushing now?

 

Not unless you want/need to change your caster.

Jeff

 

What would the pros and cons of a neg/pos caster be?

 

Castor :

Looking at the car side-on, imagine an axis
line drawn through the steering axis of the
wheel, so on a car with a McPherson-strut this
line would be straight along the vertical axis of
the strut. Positive castor occurs when the top
of the axis line tilts more towards the rear of
the car (the green line in the diagram).
Negative caster is the opposite (the red line).
The benefit of positive caster is that it
provides good self-centering of the steering,
allowing the car to travel in a straight line
without constant holding of the wheel.
Increasing negative caster will increase
steering effort, weight and feel at the expense
of self-centering.

 

Thanks! So from my understanding, neg caster isn't beneficial whatsoever right?

 

I haven't found any.

Here's some more detailed info on the benefits on + caster :

Increased dynamic negative camber in turns
Improved high speed stability
Improved road feel, steering feedback and sensitivity
Increased steering weight, this can be used to overcome some over compensating power steering systems
Improves steering turn-in response during corner entry

 

so if i were to get the RCF bushing, getting the +20 offset is better than getting 0. For all those reasons listed above and while still preventing the inner tire wear?

 

If you’re just daily driving your car , go with zero.

 

It is my daily but i also take it to the canyons for some spirited driving

 

The car runs around 8°. The three values are very small increments used to balance the caster from side to side.

Changing topics slightly: if anyone wants to know what negative caster feels like just back up way fast and steer. Its super light.
The downside about 8+ degrees of caster is that when at low speed on a banked incline, the car wants to fall in the ditch so you have to steer away even if going straight.

Let me know if you have questions, spent 6 years doing it!

 

I’ll be picking up a 18 IS350 this weekend and wanting to order these. Just verifying you guys are ordering 1 of each unique part number, right? Sorry for the dumb q

 

correct, one part number is for the driver side and the other part number is for the passenger side