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Need help w/ mega cab

3K views 17 replies 7 participants last post by  trenton 
#1 ·
New to me 08 gas mega cab. I have some questions I'd like to run by you guys. I use it as my daily driver but also pull our 5 place enclosed snowmobile trailer, boat, and heavy trailers/wagons time to time.

I understand its not going to get 20mpg, but are their any recommendations for fuel saving? I was looking at getting a cold air intake. Have been told I should get 10 hp and help a little with fuel? Not looking to spend the money on exhaust or tuner at the moment.

What's the difference between the tow button and o/d off button?

I have a 'light load' button. What's that do?

I have to keep my tires over 65lbs or the light comes on...anyway around that?

Any help with any of these questions would be great. Thanks in advance.
 
#3 ·
CAI will likely not net any improvement of the MPG you may gain MPG by changing all oils to synthetic. Also replacing sealed hubs with Yukon hub conversion kit. Tow haul changes transmission settings to keep it cooler with less slipping almost same as O/D off. Gear swap will help with MPG towing and city by working engine less but may loose some running empty. with the light sounds like you need to check and reset your TPS with proper inflation pressures.
 
#7 ·
. It has a button on the dash for hauling a light load. All it does is change the tire pressure monitoring limits. On the door it says to keep the tires at 50psi for light loads. With the light load button pressed you won't get a warning light. If you turn off the light load button, the warning light comes on because it is expecting 80psi. I can't find a recommended switch over point between a light and heavy load. Example...over 2000 lbs turn off light load. As for fuel mileage people report 6-10 MPG but your driving style and mother nature make all the difference high head winds and heavy foot will kill it.
 
#10 ·
Well that would have been nice to know months ago...I assumed the light load would be for pulling something.

Anything else anyone can tell me about this truck that may be helpful?

What's everyone do about the cup holder situation in the back? If someone's in the middle there's no other cup holders back there.
 
#11 ·
Google can answer most of your questions. They are a beast and when maintained will go forever. With a few things like hub conversion and re gearing if your planning on towing a lot will make the engine work less and will save$$ on gas and future parts replacement. They were geared towards family life with minivan room in the back able to go to the mall and still haul your camper for family outings on the weekend they are perfect for this. http://youtu.be/rvol4GWh4U0 this shows how tough they build them
 
#12 ·
Here's my advice as a person who has driven an 08 Megacab 4x4 since the day I took delivery of the unit I ordered.

1. Cold Air Intakes only make noise and do nothing for improvement of fuel economy.
I have tried freer flowing Filters and a CAI bought a few weeks after buying my truck. All it did was waste money that could have been spent on fuel.
I have an AirAid CAI that I'd be willing to part with fairly cheap.

2. Some fuels can make a difference.
I ran a test a few years back where I ran 10 full tanks of fuel from all the different companies around my area. Shell, Hess, BP, Sunoco, Murphy(Sam's Club). I ran only the gas from 1 station at a time for 10 full tanks and ran down to near empty before switching stations and starting over again with 10 tanks from the new station. I tried to fill up as close to the same time of night with every tank full so as to replicate any supposed differences that you may read about on the internet.

Hess gas and Sam's Club gave about 1mpg less than the others did. All the other gas gave about 10.5mpg. Hess and Sam's Club, averaged about 9-9.5.

Ethanol free fuel made no difference either.

3. Programmers will not increase your MPG's
I use a Superchips 3865 programmer that I also bought at the same time I bought my CAI. While I removed the CAI, I still use the programmer. I don't see a difference in MPG but I do notice a difference in acceleration and general performance. I keep it programmed for performance and run 93 octane fuel only in my truck. It is a little more expensive than the midgrade but by only $2-3 per tank total. I'm willing to spend that extra.

Through all of it, I still get 10-11mpg in mixed driving daily. I drive about 10 miles to work in stop and go traffic. If you're doing freeway and interstate driving, you'll notice maybe 1-3mpg improvement. It's the stopping and starting that really eats your fuel.

4. Synthetic fluids won't increase your MPG.
I run Mobil 1 oil in the engine. I replaced the Differential fluids with Royal Purple and the Transmission fluid is already synthetic. I truly believe they are better for your vehicle, but, they won't increase your efficiency or economy.

You may or may not get slightly better than I do. It depends on what gearing you have in your differentials. I have the 4.10LSD in mine so the rpm's are slightly higher, therefore burning more gas.

I've tried driving with the tow/haul or the OD off engaged to see if the gearing difference helped.

It didn't.

I do coast as much as possible. One of the things I picked up from Hypermilers who squeeze every bit of MPG out of their vehicles. If you're running down a hill, I take it out of gear(BUT LEAVE THE ENGINE RUNNING!!!!!!!) You're traveling at speed, and maybe even gaining speed, while your engine is only running 7-800rpm instead of 1500-2000rpm. That will help you squeeze a little bit more mpg, but maybe just make the difference between 10.5mpg and 10.7mpg overall......

go easy with the skinny petal.

I think that's about it.
 
#13 ·
A wash and wax has proven to increase MPG.

Most things that may have increased MPG in the past don't in today's vehicles.

CAI might help with some torque or HP.

I do suggest something like Redline Fuel system cleaner every now and then.

And changing spark plugs and wires.
 
#14 ·
The 08's don't have plug wires.

I just did a plug change after 60k miles and still saw no difference in MPG's. The plugs were worn but still serviceable. I gaped the new NGK plugs to factory spec. Replaced all 16. cleaned throttle body with only very minor buildup in small area.

Still getting 10-11ish mpg.
 
#15 ·
#16 ·
Cold isn't a problem for me. It's the Stop and Go that really kills the mileage. I'm in Florida, cold isn't an issue. It's 75* now. We only get cold 2-3 weeks out of the year and that's not even days in a row. We'll be 45* at 6am and 75* by 3pm.

For Christmas, we turned the A/C down real low so we can light the fireplace.:dev

For those who do live up in the Great White North, Those grill covers would probably be worth it. I had to do the cardboard trick years ago when I spent a little time up in Waukegan, Ill. Fortunately, I was dating a girl at the time who grew up in Rochester, NY who taught me how to survive when the white stuff is on the ground.
 
#17 ·
I've read good things about the free spin hub conversion, but $1500 is a big pill to swallow.
 
#18 ·
price high quality sealed hubs some run 600 a piece so its on a few more dollars to have stronger parts easy maintenance better fuel economy and less wear better riding truck and wheel bearings seals for free spin will run 100 a side if you dont maintain them and have to replace them in the future.
 
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