OMG My Gas Mileage!!! General Question Need Everyones Help

[Lizardmen3477]

My vehicross has a pretty much stock exhaust and engine with a powergem intake(just a step up from stock nothing major yet) i only get about 225 mileage on a whole tank of gas. basically 10 miles to the gal. Its killing me. anyone have any tips on how to get this up so i get more mpg i see other vx owners getting 300 up to 450 how the heck is that possible any and all help much appreciated or it might go up for sale. Thanks

[JHarris1385]

Do a search on here.

[Joe Isuzu]

No worries Lizardmen, I'm not that much better and I have ZERO power mods to the VX. I get basically 16-17 mpg, if I get 18 I'm thrilled. I have no dreams of getting 20 or above. I don't know how some of these other guys do it. Yes, I use constant throttle pressure, very limited brake action, always in 4th when I can help it, rarely goose it around traffic and my mileage still stinks. Oh well, I knew gas mileage was one of the faults with the VX. At least we get to use regular gas!
The only thing I can think of in your case is to make sure the tire pressures are good, if one is really bad or more than one are kind of bad, that would be a cheap and quick fix to your problem. Especially given the large size of these tires. Good luck!

[VXIRONwoMAN]

I get about 400 miles per tank. I change the oil every 3k and I only use Cheveron 91 octane. every other brand makes my engine sound funny. But that is about all I do. Mine is totally stock. all my mods are on the inside. Oh I keep it really clean too...so that might help with gas mileage...lol... :)

[Lizardmen3477]

u get 16-17 i barely get 10 my pressure is right on at all times my tires r 285 60 r18. i havent a clue. i no it can get better maybe ill add a new duel exhaust and better intake any one have duel exhaust that is happy with wut kind should i get. i also change oil every 3k i use hile mileage and synthectic and all that good stuff.

[JHarris1385]

seafoam gas tank, oil, through pcv. check spark plugs, o2 sensors, injectors. Clean egr, throttle body. Change fuel filter, drain a little from the bottom of your gas tank.

[WILLY]

Check your brakes maybe they are not releasing completely,check egr valve it could need to be cleaned or replaced and check your intake gaskets.Just had my intake gaskets replaced and all my problems went away,bad mileage,bad idol,exaust smelled rich.http://www.vehicross.info/gallery/data/500/thumbs/05-Photo_5.jpg (http://www.vehicross.info/gallery/data/500/05-Photo_5.jpg)

[iamjacksadrenalgland]

i think the 18" vs 16" wheels have a lot to do with it. i bet most of the guys with the higher mileage are running 16's with stock tire size.

your 285 60 18's (i run the same size) are heavier than the stock 245 60 16's AND considerably taller. remember the profile number (60) is not a direct measurement, it's a ratio that depends on the width.

i think the speedo is off by 6% with my terra grapplers of the same size. and most of the extra weight is now located further from the center of the wheel, which requires much more enegy to rotate.

[MZ-N10]

16mpg combined on stock 16s with a pv muffler.....

[18Foxtrot]

New, 21mpg with everything stock. Now, 19mpg with K&N air filter, Bridgestone AT Revo 265/70SR16 tires and Mobil1 oil, changed every 3000 miles. Everything else on the engine/transmission is still stock.

[Lizardmen3477]

so bigger my rims and tires are less gas im gonna get as well cause i wass gonna get some bigger rims soon? i had a complete maintence done to it few months back so i think all that stuff is good but about stuff to put on a car to make mileage better is that tornado any good or the bosch plus 4 spark plugs and minor stuff??

[johnnyapollo]

A short answer on those gizmos - don't bother, they don't work.

Some engines just aren't as efficient as others - plus environmental factors and general engine wear and tear all contribute to gas consumption. I usually get around 12-13 MPG on my VX in the city - it goes up to about 16-17 on interstate driving trips. The more performance mods you have, the worse this gets - mostly because the mods introduce higher airflow or more fuel boost - this creates better response times and usually causes the driver to drive more aggressively - it all contributes to poor gas mileage. Remember the VX weighs in excessive of 2 tons with a driver - the full ladder frame and full-time 4wheel drivetrain all has its toll on engine efficiency. If you're looking for a gas saver, buy a motorcycle and swap off driving every other day - the VX just isn't a good candidate for economy gas mileage.

-- John

[VehiGAZ]

A while back someone was complaining about getting very low mileage, but they were not calculating their mileage correctly. That person was filling up, driving until the needle is on E, then filling up again and dividing the 22 gal tank capacity (instead of how much gas they actually put it) by the miles on the trip odometer. This led to an overly low mileage estimate. Properly done, you should fill your tank until the pump shuts off, reset your odo, drive it to empty, fill it until the pump shuts off again, then divide the miles driven by the actual number of gallons you just put in.

Now, I'm not trying to say that you must be doing the math wrong, but 10 mpg is unusually low, so I suspect something is fishy in the calculation.

I seem to average about 14-16 mpg... low in the winter and high in the summer. The new tires I put on last year robbed me of about .75 mpg. My Yakima cargo box or ski rack lowers my mileage another 1 mpg or so. Bigger tires and wheels are heavier tires and wheels which take more power to spin, so that will reduce mileage too.

[kpaske]

Right, what VehiGAZ said - and most importantly, understand what iamjacksadrenalgland mentioned about having larger than stock tires - even if you are doing perfect calculations, your data is inaccurate because larger tires throw off your speedo/odo, so it may appear that you are getting much worse mileage than you actually are.

I've got 33" tires on 16" wheels, and I estimate that my speedo/odo are off by about 10%. Adjusting for that difference, I probably get 12-15 MPG on average.

[nfpgasmask]

I just ordered Tone's scan guage. I have never used a scan guage before so now I am wondering if it will give me accurate MPG calculations....we shall see. I'm really bad at math so I could use the help....

All I know is that when I get on the open road and drive for 2 hours at 85-95 MPH my VX CHUGS gas.

:) Bart

[Tone]

You'll need to use something like the miata garage tire calculator if you have changed tire size to see what percentage your speedo is off and then you can set the ScanGauge to take that percentage into it's calculations. I use MPH display of the SG on the dash of the '55 since I've gone to a taller tire. Keep the air pressure at max in the tires and drive conservatively but it is what it is and if you need MPG, this the WRONG vehicle.

BTW, stock tires are almost identical height/diameter on the 16" and 18". Come on guys, don't post INCORRECT information, it just confuses the newbies. Now the 18" rims could be heavier but I would not expect more than a few pounds - anybody have those specs? And if so, that would be more of an onroad handling issue when pushed.

1999 245/70/16 Diameter 29.5", 6.8" sidewall height (comfortable)
2000/01 245/60/18 Dia. 29.6", 5.8" sidewall height (less flex)

And yes, the wheels are interchangeable between ALL years.

[JHarris1385]

Hey Lizard, did you ever get your gas mileage back up?

I am sufferin too. I get max avg 14mpg.
Im about to make a post about it though cuase of me CEL code.

[nocturnalVX]

I get about 400 miles per tank. I change the oil every 3k and I only use Cheveron 91 octane. every other brand makes my engine sound funny. But that is about all I do. Mine is totally stock. all my mods are on the inside. Oh I keep it really clean too...so that might help with gas mileage...lol... :)

Then you go to Moab, and want skidplates/lift/bigger tires... there goes the gas mileage!!!
:_brickwal

[rowhard]

Hey lizard, I have my shoes on right now so can't do the math. But I have 285's too and it is a increase of 6%. So, what ever 6% is of 225 added is still crap,... but, ....well,.... I guess we didn't buy our beloved VX's for the MPG. Of course I CAN SAY THAT since my commute is 6 miles one way to work. If we go anywhere, we take 'she who must be obayed' new Suzuki Grand Vitara. Totally boring but I didn't buy it or drive it, I just wash it, put on very dark sunglasses and read a book while she drives.

[Jolly Roger VX'er]

Just filled my tank up yesterday and she did 17.5 mpg with mixed driving. I didn't compensate for slightly bigger tires (stocks are 29.6 in. diameter and my Revo's are something like 30.2 in. diameter IF I remember correctly.) I am Supercharged with cold-air intake plus K&N cone filter and am running Mobil 1 Synthetic lubricants for everything.

If your mileage is much worse..as mentioned in previous post...check your brakes (especially rears) to make sure your caliper sliders are releasing properly, which would show up as uneven pad wear if they are not.

I had starting issues a few years back and changed out my Fuel Pressure Regulator which resulted in much better mileage too.

[kelvin]

just another mpg figure for people to reference:

my scanguage II lists my average mpg at 16.5.

the speed has been gps calibrated and my "miles till empty" is accurately calibrated to within a mile (+or-). so i assume 16.5 mpg is accurate.

daily commute includes 80 miles of highway driving and 10-15 miles of city.


edit: stock tires and a/c on low 25% of my drive time (guestimation)

edit: edit: i began using cruise control for my 80 mile rt commute and have increased my milage to 17.6. It doesnt sound like a lot, but it's another 20 miles a tank....

[ZEUS]

I had great results with Marvel Mystery Oil recently. I was going to put some in the crankcase and the fuel tank but used it all in the fuel tank over a couple of tank fills instead. It increased my mileage while towing. I got 225 miles per 20 gallons on the first two legs while the oil did it's job. After that, I got over 300 miles per 20 gallons... towing!


Disclaimer: No tire or gear changes were taken into account while estimating for this post. I suck at math.

[1CROSS]

Has anyone ever heard of putting 2oz. 100% Pure Acetone to 10 gallons of gas into their Vehicross or any other vehicle to boost the mileage?Here's a site to read into:(www.pureenergysystems.com/news/2005/03/17/6900069_Acetone)

[JHarris1385]

Zues: what is this MMO you speak of?

[ZEUS]

Zeus: what is this MMO you speak of?

Well, duh, it's a marvelous mystery! :p Nah, forget "3-in-1 oil"... I have used Marvel in the past in my air tools for lubrication, vehicles that have sat for a while - top cylinder lubrication, and crankcase additive. I think this was the first time I put it in the fuel tank though. It is great stuff, you can even use it as a gun cleaner and on thread taps! I am thinking that adding a shot of Marvel in the oil and in the fuel system, and then later, using the sea foam treatment, changing the oil, and then using the Marvel indefinitely will help prevent that sludge induced 3.5L failure from occurring. I get it at Napa, but I think all auto parts houses carry it.

http://www.marvelmysteryoil.com/

[Lizardmen3477]

I have had an increase in MPG but only cause i got new rims and tires. I bought me some nice new 22's. I get bout 13-14MPG. guess thats as good as im gonna get until i put my bigger dual exhaust on. :)

[Techy-D]

I've gone from about 15.5Mpg to about 17Mpg over the last 3 tanks. I asked they guy at the un-service station (Chevron) what they have been puttin in there and he said that they quit using the Ethinol for the winter. Most people see a mile or two mpg increase without it. He said that some stations use it year around, so I should check before buying if I like higher mileage.

[Jolly Roger VX'er]

Just came back from visiting family on Memorial Day and wanted to experiment on total max. highway mileage. I topped off at the interstate and drove 135.2 miles with cruise set at 61 mph 'cause my slightly larger tires seem to throw the speedometer off by 5 mph....so I should've been traveling 65/66 mph, which seemed right with the traffic in the slow lane.

The VX consumed 5.884 gallons of premium (I have SC) after traveling 135.2 miles. Therefore, drumroll..........I got 22.97 mpg! This is inline with what I got on my trip to a VX meet 2 years ago from PA to Vermont running with cruise on @ 65 mph.

*I also cleaned my K&N cone filter on Friday and let it dry overnight; then re-oiled it on Saturday. She definately felt zippier!

[Dino]

Normal island style driving I'm getting 14.2 mpg.