As of last week I started to track my mpg. the way I have done it so far is I set the trip meter when I fill up and then drive till its empty. Take home much I put back into and divided miles traveled by that. I do alot of highway speeds (50-60) but don't drive long distances(I live in an area where everything is branched off of a major highway and most of the roads are at least 45 and up). I pretty much drive like grandma and my jeep almost never gets close to 3000 rpm when accleration.

At this point im close to 10 MPG. That is crazy low and I really need to boost it. I still have stock gearing (3.55), No lockers(possible limited slip in the rear, checking with dealer on monday), 30 inch tires, no performance mods. My check emissions light has a tendancie to come on and go off, I know its the not the cat or anything behind the cat because I replaced that all brand new back in Sept.

I know last year when the light started to come on my mechanic checked it and said that the 02 sensors are screwy and will prob give in a year so I assume that its for that. I still plan on getting it checked next time the light comes on.

Another way I figure to help my MPG is to do a tuneup. I am asking what everybody thinks is good ideas for a tune up. I figure spark plugs, and fuel injector cleaner is a good start. Money is not an issue for me at this point. I do know that I plan on a bored TB for easter and that in the next couple of months i will do a #19 ford racing fuel injector mod. (yes I know these two mods arent exactly mpg friendly but with them I still should be able to get at least 15mpg with the way I drive.)

Any other things that people can think of to give me some better mpg?

 

Distributor cap and rotor button. Maybe a little Seafoam action too.

 

What is seafoam, what does it do and how do you use it? Btw I have an 01 so I dont have a dist cap or rotor I think.

 

no cap rotor and wires for you then. get the plugs that came from the factory, i think they are ngk platinums. the older jeeps take champs, but yours is probably different. don't expect great gas mileage, mine is tuned up, new fuel filter air filter and 02 sensor and i get 12-13 in the city. however i do get 20 on the highway staying at 1950 rpm's.

 

I am expecting a little better because I know during the spring I could go a week and half to two weeks before filling up. So this has been a steady decline.

 

Check codes...just because your light isnt on doesnt mean you dont have a stored code. I average 15-17 MPG city/highway and i dont drive easy.

 

Well if the stealership will check the code for free then ill do it tommorow when I stop by to check my vin for equipment on the jeep.

 

did he just say stealership and free in the same sentence???

 

yes I know, but I can at least try or else Ill go to Advanced cause they do it for free.

 

You sure your speedo/odo is accurate? Maybe you are actually going farther than you think on a tank of gas.

 

That I havent checked, but If it is off I doubt by a large enough margin to cause this. I will get the spedo set after I lift and regear.

 

Seafoam is http://www.seafoamsales.com/motorTuneUp.htm .. It helps clean your intake, crankcase, and gas if you use it there too. They have directions on how to use it, it is pretty straight forward. I would say use it a couple hundred miles before your next oil change, then when you change the oil.. Use some Engine restore, and some MMO along with your oil of choice. For Dyno oil I recommend Valvoline, as it has zinc and our motors need it! Otherwise, for full synthetic I recommned Amsoil.. then if you dont have access to that then either Valvoline SYnpower (has zinc as well) or Pennzoil Platinum.

 

I used a can and a half of seafoam about 700 miles ago I didn't see any real fuel economy change but I know that it cleaned my engine out. I used it in my gasolina tank as well as dumped it right in my intake manifold by taking the hose off that conects it to the air box. I'm not ssure If this is the right way but whatev. Maybe it's just me but I noticed that it may have made my engine rev up unusually high but maybe that's just because I was paying more attention to all my stuff. I've heard o2 sensors are a real good idea I'm doing mine this spring along with my tune up

 

you did the seafoam wrong.
the tube from the airbox to the valve cover is only gonna dump it right into your valve cover and eventually into the oil.
you need to use the brake booster hose. its a vacuum source and it will get inside the intake manifold, runners, combustion chambers etc.....