Kia Optima Forums banner

1 - 6 of 6 Posts

·
Registered
Kia Optima LX
Joined
·
6 Posts
Discussion Starter #1
I was recently looking at a 2020 hyundai sonata se and kia optima lx side by side. Under the hood they look practically identical in parts. Same engine, same transmission, same air intake, cooling system, break system etc etc. But I noticed underneath, the sonata had aluminum control arms while the optima had steel control arms. I'm just curious if there is a reason for this difference?
 

·
Registered
2011 Kia Optima
Joined
·
2,762 Posts
Stamped metal arms are just a way to cut cost, but if you look at the Optima in the early years, you'll find that aluminum and steel arms were used within
the same year. At one time I thought it was just where the car was manufactured, but found that to be untrue as the Georgia plant also had cars with the
aluminum arms. I personally would rather have the aluminum arms, but certainly it wouldn't be a deal breaker. Guess two trains of thought, the aluminum
arms are much more expensive and the metal arms had a tendency to rust, however, the metal arms can be used to replace the aluminum units as was
done by one of the posters on the Forum.
 

·
Registered
Kia Optima LX
Joined
·
6 Posts
Discussion Starter #3 (Edited)
I have also heard metal control arms are stronger. Aluminum might bend? I wonder if Hyundai calculated that Kia owners are younger and more aggressive drivers? So therefore, the optima gets metal and the sonata gets aluminum?

On the topic of rust, the metal control arms look like they have a thick protective factory coat.
 

·
Registered
2011 Kia Optima
Joined
·
2,762 Posts
Don't jump to that conclusion too quickly. Aluminum has replaced steel, lighter and stronger depending on the process. Many year ago the Corvette was one of the
first to use a hydro-formed aluminum frame. The frame was formed by using high pressure water, pretty neat.
Also, Kia had the 2G/3G Optima returned to the dealer to have a substance/coating applied to the undercarraige to prevent extreme rust. Something like closing the
barn door after the horse escaped.
Here's a 5 year old rear LCA off my Optima:
249143

249144
 

·
Registered
Kia Optima LX
Joined
·
6 Posts
Discussion Starter #5
Wow thats crazy rust! How did you know to take them off and replace them? Did you notice by looking at them or did something fail or go wrong? Did the dealer charge you?
 

·
Registered
2011 Kia Optima
Joined
·
2,762 Posts
Knew it was pretty bad, but took the car to the dealer to spray the goop on the undercarriage, but the service advisor
came into the waiting room to tell me the car shouldn't be driven, so I had them leave the goop off the arm and replaced
it a couple days later, and can you believe, even after sending info to the NHTSA there was still no recall.
 
1 - 6 of 6 Posts
Top