16 MPG ..... Please Help !!

[PhileasFogg]

Sentra ..... My goal here is not to fuss with you. You have offered little in good advise and a ton on the way I should live my life and how I should conduct myself and spend my time while on vacation. Only an idiot wouldn't change their driving habits when trying to improve their fuel mileage. Of course I use fuel saving diving habits. I am not looking for a magic bullet. When racing there were times I needed to remove 100lbs from a racecar. Well, I didn't look for something that weighed 100lbs I could take out. I looked for 1000 places where I could remove a couple ounces. That's the magic bullet. I'm trying to find very small increases that are cost effective. I was getting 12.7 MPG around town the first couple of days. I increased my tire pressue to 75psi and went to 13.8 MPH. That's an increase of 8.7% and it cost me nothing. I am simply on here trying to get real world advise from people who have tried different products and ideas. I'm not looking to have a house that gets 30 MPG. I'm looking to have a house that gets as good of mileage as possible.

[theholycow]

Originally Posted by PhileasFogg

holycow ...... I lot of the stuff I have read suggest car makers are worried about emissions alot more than mpg. These sorces suggest there is alot to be gained from getting air in and out of the engine more efficantly. Do you think this is bunk?

While I agree that they are more worried about emissions than fuel economy, I don't think it has a detrimental effect on intake and exhaust plumbing. 30 years ago it did (the exhaust on my 1980 Buick is abominable) but the technology has completely matured. Both issues are far overshadowed by the market's demand for more power, most of which you won't be using (if you have any interest in saving fuel at all) and therefore even negligently designed plumbing will have no effect on you.

If you do anything with your intake, do a homemade warm-air intake. It probably will have zero effect on fuel economy but it's the only plumbing modification that has a chance of helping (and maybe paying for itself).

For exhaust, it may be possible to improve fuel economy slightly with longtube headers and mandrel-bent pipes but they will never ever pay for themselves, not even in a million miles.

(Again, this all applies to people who aren't racing or otherwise running WOT@redline all the time.)

[JanGeo]

PF are you running a scangauge? That engine is probably burning more tha half a gallon of gas an hour just idling. Looks like it takes 7 quarts for an oil change every 5000 miles will add up quick if you are driving a lot. Synlube cost more up front, but over a few oil changes you break even and don't have the down time while on the road for oil service. It typically gives you a certain percentage increase in gas mileage for each of the lubes you add to the vehicle. Engine oil is 8-10% increase, transmission 5%, power steering 1-2% increase so you just add that to the oil change savings and it's a win win. It improves ring seal, reduces blow by, increases hp and runs cooler and quieter from the reduced friction. It works at getting you more for the gas you burn under all conditions. And you don't have to think about it or change your driving style to see the benefits.

[PhileasFogg]

What about Air Tabs? Are they too good to be true?

[kit352]

im not sure i can help too much but ive been trying the r/v mpg increase for a few years now. all i can really offer is some of my ideas but i never really kept a log on it.
the first thing id get is a scangauge or equivilant. thatll help more than anything else ever will. you dont know were your going unless you know were youve been.
id consider a wai but would carefully consider it. it may not be in you best interest to hurt power if your gonna be fully loaded and traveling in mountains. a wai will have a toll on hp on hot days. doesnt matter much on cars and such but a loaded rv is a completely different story.
add alittle air to the tires. everytime i overinflated the tires drivability took a huge hit. the soft cushy ride was gone and road noise increased. wasnt worth it imo. try and see for yourself.

[Jay2TheRescue]

One ton GMC vans are not OBDII, and a scangauge will not work.

[theholycow]

Jay, a 2008 model is required by law to be OBDII I thought, unless there's a weight limit above which it's not required...but since they're using the same powertrain as in many 1500 models, I imagine it's equipped with the same PCM and therefore is OBDII.

Edit: OBDII is required on vehicles with GVWR of 8500 pounds or less and a 3500 van is certainly rated for more...but I doubt they'd eliminate the OBDII port and create a whole new engine control system to put the 6.0 in the 3500.

[kit352]

Ive got an 06 3500 at work that has the port. never checked to see if its real or just gm being lazy and leaving it there. I thought all new vehicles had to have it.

[Jay2TheRescue]

Light duty vehicles are the only ones required to be OBDII. Our 2000 GMC 3500 van is not OBDII, and my dad's 2008 E450 Super Duty is not OBDII either.

There is a computer port there, but its not compatible with a scanguage. The only full size vans compatible with a scangauge would be the 1/2 ton models 1500 (Chevy/GMC) or E150 (Ford)

[JanGeo]

Rats on the obdII