Kia Forum banner

1 - 2 of 2 Posts

·
Registered
1990 GMC K1500, 2005 Kia Spec5
Joined
·
4 Posts
Discussion Starter #1
Hey everyone,

I bought an '05 Soectra5 a couple of days ago. I've noticed that it runs great, no issues yet besides the airbag light. For some reason, the "passenger airbag off" light doesn't turn on when the seat is empty about half the time. I'm just wondering if this is a serious problem, or not, and how to fix it. I also forgot to mention that when this happens, the red airbag light in the cluster also stays on. My other question is probably really dumb, but I'm curious; the car was advertised as a 5 speed manual with overdrive. How do I use the overdrive? In my old vehicle, 5th gear was overdrive. Is anyone able to help me? Thanks!
 

·
Registered
Cerato S Hatch Auto
Joined
·
1,236 Posts
Can't help you with the mysterious lights.

5-speed with overdrive simply means that you could describe 5th as an overdrive gear.

Overdrive was originally an add-on extra ratio that could be activated (sometimes electrically) to reduce the RPM at cruising speed. The top gear in many old-time gearboxes was a "straight-through" shaft, and the extra gear stepped up the final drive by about 20% (Thereby reducing engine RPM). Typically, the effect was to give more relaxed motoring, but in most cases the maximum speed in overdrive was actually less than the original top gear.

Modern gearboxes have 5 or 6 gears, none of which are necessarily 1:1 and almost certainly not "straight-through" like the old 'boxes. The ratios are closer, and the top gear on many KIAs is about 0.75:1 and that is in some senses is overdrive. Again, most 5 or 6-speed cars do not reach maximum speed in the highest gear, and that is another definition of overdrive.

For example, 6th gear in our Cerato 2.0 auto runs out of steam at about 150 km/h, at which stage the engine is doing 3000 RPM. If you wanted to push on, 5th gear would kick in and take you to about 185 km/h. The manual 6-speed Cerato has overdrive 5th and 6th gears, by the way, but that's really academic.
 
1 - 2 of 2 Posts
Top