Hows it goin everyone, new to the forums, looking for some advice.

I have a 1998 Dodge Ram 1500, 5.9 V8 Magnum 4x4. It has a 5 inch suspension lift, and 2 inch body lift, with 37 inch tires.

Currently im getting (Please dont laugh!!) 9 Miles to the gallon, and as you can guess im filling it up pretty often. I dont know too much about trucks, some, but still learning. Waswondering ifthere is a way toraise the miles to the gallon.

If there is anyway to, please list the price it'll cost along with it. My buddie says lower the tires from 37, to 35's or less, would a smaller tire make much of a difference, if so how much? I dont want to go too low, I love my monster tires.

Any advice would be greatly appreciated!

Let me know if this is the wrong part of the forum to post it in.

 

Buy a used geo. bout 1000$

 

Use the search to find gas related posts. Theres been alot. There is a wealth of information on this site. With a truck like yours with the lift and the big tires anything you do to try and get better gas mileage is going to cost more then you would save in gas.My truck has no lift and I havn't done any mods to it yet and I get 12-13 mpg. If I drive it like I stole it then my mileage drops to about 10-11. I expect to increase my mileage by getting rid of the deathflash, moding my intake, and porting my TB. I would like to see 15 mpg but, if I don't get any gain I'll still be happy. I bought the truck knowing it was going to guzzle gas. The other thing you need to look at is what gears you have in the rearend. It' not uncommon for people to do the big lift and big tires and forget to change the gears. Although with tires that big I think you would have noticed that your gears were to big.

 

whats this "Deathflash" you talk about getting rid of? and how can you port the TB, and by porting what does that do?

 

what gear ratio do you have? if your still at stock (3.55 or even if you have 4.10) with 37's that will be killing you (ither 4.56 or 4.88 would be better) yes smaller tyers would help but only going to 35's probley wouldent be to noticable, these trucks get poor gas milage and the bigger tires and more lift only makes it worse

 

9mpg isnt bad at all. be happy with it, and get used to watching your cash fly bye bye. If your simply modding for fuel econ, dont its not worth the money; but if you want to mod for other reasons, do that.

 

The "Deathflash" was a Dodge TSB to stop pinging in our trucks. They used it as a bandaid instead of fixing the real problem. Your intake manifold is alluminum, and the plenum plate is steel. Because they used two differnt metals that expand and contract at differnt rates it was very common for the gasket between them to tear causing leaks. The leaks would make the truck run lean causing detnation or pinging. The proper fix would have been to install an alumminum plenum plate. Dodge opted to just reflash the PCM and retard the timing so that the truck didn't ping anymore. This reduced power and MPG. To get rid of the deathflash you need to do the CPS mod, or have the pcm reflashed by B&G, or use a hypertech. Some people have been able to use the 91 octane setting on a hypertech and still run the regular grade gas. Fixing the deathflash could expose a leaking plenum. If your plenum is leaking then you need to replace it.

You can buy an already ported TB from Dan the Fastman. Everyone on this site will swear by him. I think it's about 200$. I'm going to port mine on my own. I know I won't be able to get the same results but I like to do all of my own work. If you look at your TB it has all of these air horns on the top. Cut them off and make the top of the TB flat. Next if you look down the hole you might notice that the bottom of the TB is narrower then the top. I think that the measurment is something like 50mm on the top and 48mm on the bottom. Just shave out the bottom until its 50mm on top and bottom.

 

Is there a stamp or serial numbers on the rearend that can identify my gear ratio, without having to take it in?

 

It should have a tag on it, mine does and it says 35 on it, which means 3.55 gears.Also should tell under hood, raise the hood and look up.

 

there is a cupple places to look for the gear ratio, tag on one of the bolts on the pumpkin, sticker in the glove box or sticker on the underside of the hood if you cant find it any of those places then get a build sheet se how hwere https://dodgeforum.com/m_922730/tm.htm and here https://dodgeforum.com/m_292535/tm.htm , all of these ways will tell you the STOCK ratio it had, now if it has ever been changed the only wa to tell is to pull the diff cover off, count the number of teath on the ring and divide it by the number of teath on the pinion eg 41 teath on ring, 10 teath on pinion 41/10=4.1 (4.10gears)

now that said if it you put the lift and 37s on it its mostlikey stock and if its stock about a 95% chance its 3.55whitch is way to low for 37's even if it is the other stock options (3.73 i think,or 4.10) still too low for 37's