So is the story with so many of us Ram owners. 2005 Ram 5.7 4x4.

113K. Putting out about 10MPG on the highway.
Plugs changed about 1500KM ago. Champion to NGK G-power.
Not throwing any codes.
Exhaust manifold had a broken stud on the passenger side, replaced the gasket and all hardware.
I'm in Ottawa, Ontario. Driving is about 400K/95L. Running 94 from Sunoco.
Not being heavy on the pedal either. Staying under 115k on the highway.

How big a difference will oil make? Changed about 4K ago.
Air filter done at same time.
O2 sensors seem to be fine, like i said no codes.

Any ideas??

When i bought the truck in August i was up to 600K to a tank.

 

Welcome to the Ram. lol Cold temps will bring fuel milage down. And did you put bigger tires on. I lose 2-3 mpg just by putting my winter tires on.

 

When is the last time you cleaned your throttle body? Big MPG robber on these trucks...

 

Over time things start to wear out which means the engine has to push harder. Bearings become harder to turn. Fluids start to become harder to push. Tire wear may cause more resistance. Also they are starting to sneak in ethanol into the gas which brings down the distance per liter greatly. The older the oil the harder it is to push through the motor and filter which is a loss in efficiency.

 

10 mpg on highway? or did u mean around town, cause i get 12 around town and 17 (MAYBE) on the highway, depending on the hill of the great state of By God West Virginia. and hammer u mentioned the throtle body.... never thought of that on before, good call

 

Thanks for the welcome. I thought I was on this forum before, but when I posted it said 1st. I have only put 15K on it since I bought it. I did change to BF Goodrich 285 55 20's which were the same size as my old Eagle GT2's that were bald as hell. So the tread is something seriously different.

As for the throttle body, I don't even know how to clean it. So it's safe for you to assume that it's never been done. I know the cold will drop MPG's but it's hard to put my finger on, because I changed the plugs the same weekend I put her new shoes on and that's the same weekend the snow came as well.

How do i clean the TB?
And gonna swap to full synthetic throughout the truck this weekend. I'll check back to let you guys know what my outcome is. Thought the 94 had no Ethanol in it?

 

frog pm...and yes when you clean your tb it shows it runs smoother and the throttle response is better....

 

5.7 Hemi--->>> Always use OEM Champion copper plugs...

But that aside, did you gap the plugs correctly??? Did the poor gas mileage begin before or after the plug change???

I will agree that your TB probably needs to be cleaned, and you're losing some mileage there... Here's a shot of my TB 20,000 miles after I cleaned it the first time:


and after cleaning:


Just remember with the TB, the dirt collects on the inside, the outside will look clean when you take the breather hose off of it... It's easy to clean, take off your intake, then you have 4 bolts, I believe 10mm, and 1 electrical plug.... 30 minute job if you don't have a cai, and if you have a cai maybe 15 minutes...

 

I can understand hoiw the T/B gets dirty and can affect MPG's a tiny but, but not severly. The opening is only reduced maybe by a few mm's so it's not like your getting choked off by a little carbon deposit.

Semi-clogged up egr valves won't throw codes if they are still "breathing", but can severely effect MPG's compared to a slightly dirty T/B. BUT the combination of a few things can bring you way down.

10mpg you say? By what the overhead console? Do you have a remote starter or let your truck warm up in the morning? THAT will really reduce your mpgs. My overhead console would read 8-9mpg when i get on the remote start kicks in the severe cold.