Hey everyone, Just joined the forum here and have been reading it for about 6 months. I'm going to be getting a used 2008 H3 with the adventure package and was hoping some one could help explain to me the pros and cons of both transmissions, it would be very helpful.

 

Howdy and welcome.

The auto trans costs more, the manual require hand and foot work. Very few 5speeds are sold here in the US. The 5 speed may gat a tad better MPG on the Hwy.
Matter of pocket book personal preference I would say.

 

Well.....
Auto Pro's
Easier on the left leg in traffic
Easier for a novice off-roader
Don't have to worry about burning up a clutch

Auto Con's
Sluggish/slow to react
Only 4 gears to choose from (larger gaps between gears)
Tend to run hotter
Less efficient (although modern ECT's have closed the gap )
Cant pick and choose the gear as quickly in off-road or emergency situations

Manual Pro's
Choose whatever gear you want whenever (to an extent) you want
Better crawl ratio/gearing
More gears to choose from
More efficient (slightly)

Manual Con
Traffic
Keeping momentum when going up hill from stop
Harder (more skill required) when off-road and rock climbing
Traffic
Harder to hold that 44 oz big gulp ;-)
Traffic

Every car I've owned has been a manual (mainly sports cars). Every Truck, an automatic. I just prefer auto in truck/towing/off-road situations. HATE the 4 speed, but oh well. I guess it depends on what you are doing with the truck.

 

After I installed the "PCM4less" computer my shifts in my auto are nice and crisp. Parasitic loss of the new automatics are nill.
Stirring a gear box was fun when I was young but now the auto suits me fine! Even my Corvette has an automatic.

 

^^^ Pretty much everything they said – especially the Big Gulp ^^^

My only disagreement with the above comments is in the significance of the difference in efficiency (mpg). The difference can be pretty substantial - 10% or more is not at all unrealistic depending on how you drive and under what conditions. In terms of mpg, I'll grant that an automatic is probably better in stop and go city driving. I suspect that there’s not much difference on the highway (not sure why there would be). I've found, over the years, that a manual is far better when cruising around the suburbs with minimal stops. I’m speculating that maybe this is because it tends to downshift at various thresholds while your decision whether or not to shift is based on what you know you’re going to do next (or maybe you’re just lazy ). In any event, there are many situations where you might tend to stay in a higher gear than an automatic would, resulting in less gas used. Add to that the benefit of coasting to a stop – something an automatic typically doesn’t do on its own (I’m sure there’s a good reason for that, though I can’t imagine what it might be). I've been getting around 18 with my H3 in the 'burbs in the month since I bought it - getting better as I keep an eye on the Scan Gauge. Before that, I was doing a pretty consistent 20 with my ’04 GTO, while a friend of mine with an automatic was doing closer to 17 under roughly the same conditions. Both are higher than I would have expected based on the EPA numbers.

 

I drove a big rig for five years, so I am partial to manual tranny. I will try to keep to facts . . .

Manual Pros
Higher crawl rate (lower gears - about 69:1 with adventure package)
Better gas mileage (I consistently get 20-22 MPG, but I also have 3.5L with Gibson cat-back exhaust and K&N intake)
Can use starter to pull out of difficult situations (clutch safety switch has been bypassed on mine)
Unique (I always get comments from people that think I put the manual in it)
Runs cooler when pulling steep grades.

Manual Cons
No after market parts (custom pedals, shift ****, and gauge background available only for auto)
Lower towing capacity
Not good for sand (a higher gear rate and auto shifting can be a big help in sand)
Rare, may be hard to find people to work on it, even though it is the same tranny as the Pontiac Solstice
Many people in car washes or valet lots can not drive a stick.
Wife may not like manual shift (I am not going to give any more details to protect myself)

 

I wanted a manual, but the dealer did not have any in stock. The dealer told me they have only sold 1 manual in the last 12 months!

 

Yep, you are more than likely right!! And I was the dummy who bought one and only 5-speed!! Perhaps I grew up since my last manual tranny, but I sure hate shifting now!!

 

While the manual in the Hummer is not nearly as much fun as the 6-speed in the GTO, I'd hardly call it a hassle. As long as you know how to shift, you'll be doing it unconsciously after a week or so. Before the GTO, I hadn't used a clutch in over 20 years, so it took a bit of getting used to. Another advantage of the manual is that fewer people will borrow it

 

I had to order my H3. I wanted the 5 speed with a sunroof and Adventure kit . . . none available in the western US, including Sewell!