Okay so I have a 2007 H3 with the I5 and I am deeply considering getting an H3 Aplha. I want to know if the 5.3l is worth it, and if there is any other differences?

 

other than the difference in power, I think it's worth it if you have a practical use for it's application

 

they are going fast.
all new h3 could be gone this month

i hear mileage is similar,,??

if u need a v8, its alpha,,towing??.
otherwise the i5 has more power than needed.

in lo range,ist gear it could lift itself up!.

in lo/lo u go 5mph at 3000 rpm! it should climb a mountain. in my 07,i5 i got 20mpg, so far in my 10 i get 15

 

The V8 is smooth and powerful. Feels great and no shuttering. I believe it will last last longer and run better than the I5. I am biased, but when you put your foot into it, the little H3 gets up and moves. I smile every time I drive it, but I guess those with the I5 do the same, 'cause there also driving a Hummer. The gearing is different and the mileage I get is 13 to 14 mpg average with a lead foot.

 

Those 5.3l have endless power adders I have a gto and you can swap the whole top end over to the 5.3 heads intake manifold ,throttle body and gain 40-65 hp add a cam your lookn at 100+ hp with tune if you want some serious ponies.

 

I wouldn't give mine up for anything! But....the mileage is substantially lower then what I've been reading you guys get with the I5's. I have been checking my mileage since I got it. I don't have a lead foot, and have been getting about 12.5mpg ave. It made a big difference at the end of the summer when I stopped using the air conditioner.....jumped up to 13mpg. An added bonus....there's a thread that talks about changing the alternator on the I5's. Says you have to pull the intake manifold, air conditioner compressor, or inner fender etc., etc........the Alpha has it mounted right on top!....I could probably have it removed in 10 mins!

 

I have owned an 06 with the 3.5, an 08 with the 3.7 and now a 10 Alpha with the 5.3. I do not tow. The stock 3.5 was adequate for me. I totaled the 06 and bought a new 08 with the 3.7. Mods included an Airdoc intake, Magnaflow Catback exhaust, PCMforless tune and the Alpha air intake snorkel. Those mods made the 3.7 a little screamer. In daily use, there was not a great amount of difference between the modded 3.7 and the 5.3. Like I said I don't tow and I'm sure if I modded the 5.3 it would make a big difference. For my use, I was happy with all 3 engines. Alpha get about 1 MPG less than the I'5s. Maybe it will last longer because it don't have to work as hard, but maybe not.

 

IMHO, the stock 3.7 I5 is a bit underpowered. I just bought mine a few days ago and while I'm satisfied with it for now the 5.3 would be much better. I just wasn't willing to pay the difference in price. If you already have an I5 and the only reason to trade it for an Alpha is the desire for more power, you might be happy just modding the I5 like RKSmith163 described. If I decide the I5 is too slow that's the route I plan to go. Much cheaper than trading up to an Alpha, and based on RK's description there probably isn't much difference in power.

 

I have an 06 H3 with an I5. I have also done about the same mods mentioned earlier. I have the Corsa dual cat back exhaust system, Magnflow resonator, GM High Performance Air Intake and a PCM for Less tune. The H3 runs like a champ and literally handles like a sport truck. I also have 20" Moto Metal wheels with 275 x 55 street Toyos. The torsion bars are cranked up for leveling purposes only. I love my set up and the way it handles far exceeds my expectations. It is not a daily driver but has 23,000 miles on it. I bought it new in Dec. 05. Good luck with yours.

 

Thanks for the feed back everyone, it is really helping me with me decision. It pretty much sounds like there really isn't a mpg difference, I baby the hell out of my H3 so i get decent gas mileage. I just really want a V8, Ill probably end up supercharging it and throwing on a nice exhaust. I was also considering looking into some H2's?