Hey you guys, gals! I'm getting 10-11 mpg on this truck. Is that common?

It is the 5.9l but dang, 10? 11? Really. Its prob these tires that came with it when I bought it 4 or 5 months ago. Theyre 33's on 15' rims. I got no extra weight. Not even a tool box.

Will a cai help? If so, you know of any that are better than others? And any to STAY away form?
Would diff plugs help? Its tuned sweet, sits at 750 rpm's solidly, tach needle never bounces, never even shakes, runs great.
l know its pretty stock. Thanks for any suggestions.

 

What gears? If they are the typical 3.55s, then what you are getting is going to be normal.

CAI won't make any difference at all. They draw air from the EXACT same place as the stock system. You *might* get a LITTLE BIT more power north of 5K RPM with a CAI, but, that is the only improvement you could expect. You would be better off just getting a high flow air filter, and toss it into the stock box. Leave the stock system intact.

Regearing your axles would make the biggest difference..... but, spending 1600 bucks on having it done seems just a tad expensive for the 1 or 2 points per gallon improvement you would see..... Side benefit though would be your trans would last longer.

Basically, you have a big, heavy, truck, with a big, thirsty motor. I think my best mileage on a tank that was just around town, was about 12.5....... Of course, mine is a 3/4 ton 4x4..... so, I don't expect stellar numbers.

 

Ok, well that's not so bad. Not to bad of news. At least I wont have to spend money or do any extra work! I'm off today so trying to get some of the Ram's stuff done.

There is a bad catalytic converter under there. Think that would do anything if I got it fixed the right way? I think I need to ask about the catalytic converter in the other section. Can you go to the cc post and look at that question for me?

 

Clogged cat will affect mileage..... Of course, replacing it may only be a temporary measure.... need to find out WHY it clogged up. Fixed your plenum yet? How old are your O2 sensors? (replacing them may even help with fuel mileage.)

 

No sir. Didn't fix plenum yet. But I did put that big round rubber gasket ring thing on there, at the top of the throttle body opening, that you set the air box thing on?

Well, when I put that on, it stopped that cutting out and vac leak sound, where there was that air sucking sound real bad, that issue is fixed!

When I was at you pull it yard, I noticed that some of the Rams had that black rubber ring around the top of the throttle body, under the big plastic part that sits on the opening of the throttle body(some actually didnt have one)
So I grabbed the best looking one and threw it on the Ram when I got back that day and I couldnt recreate that air sucking cutting out until almost shutting off problem for nothing! That was all it needed the whole time, for that particular issue anyway. And oreilys sells em for like 5 bucks!

That dont mean theres no issues with the plenum though. I dont remember a plenum problem I dont think? Maybe I forgot! That is HIGHLY possible.

I think the cat probably went bad because it's probably the factory junk one that had recalls on them. Maybe? The entire exhaust looks like it's still stock, like from 98 at that.

So I can cut it out of there and put back in some type of insert? I'll get some new O2 sensors for sure if you think it has to have those. No problem.

 

Or is the best idea to get a new cc and have it installed, welded? Can I install a new cheaper cc? With clamps or something other than welding? That's prob stupid idea!!
I would think they HAVE to be welded on!

 

It can be clamped, but, welding makes sure you don't have any leaks, and it just holds better.

Installing a new cat, or not... is pretty much up to you. The only thing it does is restrict flow a little bit, and reduce some of the more noxious chemicals found in exhaust. What's funny is, I have seen testing where the trucks still passed the emissions test, even without a cat.

Replace the front O2 sensor. NTK, or Denso brand please. Skip the Bosch. Rear O2 just monitors cat efficiency, I don't think it has any affect on fuel economy at all.

 

I gotcha! And I like that whole idea. So replace the front one only? Not the rear one?

 

If you didn't correct the speedometer for the increased tire diameter, you are getting better gas mileage than you think, because you are covering more ground than the odometer is giving you credit for.

 

Easy enough to tell if your speedo is off. Use a GPS or GPS function on your phone. At 60mph, what is your actual? Then we can tell rd percentage that your speedo is off.