7.4 to 8.6? I would expect a little more out of it even for a big 20 year old truck. Are you sure nothing's wrong? Might be worth hooking up a scan tool and checking out fuel trims.

 

I average 13.5 consistently with my 07. I installed the Predator Motorsports "Rap torque" high performance ECU. Before that, I couldn't get over 10 mpg.

I feel its a great tune, more power and smooth as ever. They will send you a reworked/tuned ECU and then you need to send them back another ECU or your old one. Believe I paid about $600 3 years ago, already recouped my money.

Everything else is pretty much stock, although it's all new as I keep my maintenance up to date.

 

[QUOTE=Gavin Costigan;407184]7.4 to 8.6? I would expect a little more out of it even for a big 20 year old truck. Are you sure nothing's wrong? Might be worth hooking up a scan tool and checking out fuel trims.

short term and long term fuel trims are pretty much at 0 as they should be.
you cant get past 2 blocks without a stop sign or traffic light in the city. also can't go past 25 mph or you get a camara ticket.
most of the time you cant even do the 25 because of traffic.

 

7.4 to 8.6 is about right in the city.
I’m not sure if I have a avg mile per gallon on my H2 but it tells me how many gallons I used.
I don’t really care either, I just keep it filled up.
When I see cheap gas somewhere I remember it and in the weekend I just top her off.
If this is your everyday ride I say good luck to you.

 

As HummerZ said, new technology gives you new problems along with better fuel economy. You can roll the dice with custom tunes, cold air intakes, a free flowing exhaust system and eliminating extra weight.
If you don't wish to go that route then keeping up on the maintenance which other have already talked about, there is not much more you can do.

I have known many who have dropped some big bucks on their H2's
with aftermarket intakes, camshafts, headers, changing pistons just to end up with a few extra horses but worse fuel economy then they had before they started. Some of them shooting themselves in the foot for resale value.

Lets face it, It's one heavy rolling brick. Now you could have the new GM 6,6 Gas engine transplanted into your H2. They are currently getting about 15mpg in a 2500hd which weigh in at an average of 7k, yes you would have
slightly better performance, be able to run regular fuel and marginally better fuel economy. You would also have a new technology engine, more hp and torque but the downside, its going to cost you at least 10 grand!
The only thing that will give you super fuel economy is a Duramax conversion but now were really talking big bucks which will be nearly impossible to recoup, but you already know that.

Personally, I have had 3 H2's and other then being religious with maintenance I have found nothing that really makes a great deal of difference in fuel economy other then treating the vertical pedal on the right like it has an egg under it.

Even though its a POS and doesn't drive or offer the comfort anywhere near my H2 I find myself driving my Jeep if it's important to keep the costs and road miles down.

 

my best around town here in Florida on ethanol free 89 is almost 11.8, on 93 10% ethanol 10.7.
If my size 13 has other plans.. more like Gavin said, lol.

 

Dang…… 13….. that’s a hummer size shoe 😂

 

Thank you for your suggestion, but losing weight is not an option for me. I need some hardware upgrades, such as spark plugs, intake, exhaust, tuning, etc.

 

Thank you very much for your advice, I have noted it down. I will do some research and start the modification soon. My original intention is still to swap the L5P, but I have recently planned a road trip to Alaska, so I want to spend a little money to change some parts. I haven’t done any parts upgrade since I bought the car in 2021, and I’m afraid some parts have aged.

 

Hardware and much more.
3000HP, 0 to 60 in 2.7 sec.
But I’m pretty sure you get less than a mile out the gallon.
But you’re the MAN!!




or…….

Can’t go wrong 🤷🏼‍♂️