PDA

View Full Version : Gas milage increase!



VehiX
05/31/2007, 06:53 AM
Hey folks -

This may seem obvious to some but I just wanted to point out that I have been seeing better gas mileage from my VX after performing the following maintenance:


Flushed and filled tranny fluid
Changed out the PCV valve
Flushed and filled front and rear diff fluid


I was previously getting about 270 miles before the light came on. Yesterday I managed to get 330. When I filled up at the gas station, I put in about 20.xx gallons (cost me friggin $65.46!!!). My driving style has not changed, so I can only guess this basic maintenance helped me to achieve the better mileage :)

Anyone have opinions on this?

Current power mods:

PV 1 exhaust
Basic cone air filter

nfpgasmask
05/31/2007, 08:39 AM
Well, I changed my fuel filter, and switched to a regular K&N box filter, and I noticed an increase in gas mileage. I also change my oil and PCV every 3000 and have been doing so for a long time. Keeping things clean definitely helps. I don't know about the tranny juice, but it may also increase efficiency, which may in turn help the VX use less power to shift, etc, which may have helped, but now I am talking out of my @$$. :)

I am about 10k miles away from doing my tranny fluid/filter and diffs again.

Bart


Hey folks -

This may seem obvious to some but I just wanted to point out that I have been seeing better gas mileage from my VX after performing the following maintenance:


Flushed and filled tranny fluid
Changed out the PCV valve
Flushed and filled front and rear diff fluid


I was previously getting about 270 miles before the light came on. Yesterday I managed to get 330. When I filled up at the gas station, I put in about 20.xx gallons (cost me friggin $65.46!!!). My driving style has not changed, so I can only guess this basic maintenance helped me to achieve the better mileage :)

Anyone have opinions on this?

Current power mods:

PV 1 exhaust
Basic cone air filter

Dino
05/31/2007, 09:23 AM
That little PCV does a lot to increase mileage. That valve lets unburned fuel vapors, which are prsent in the crankcase, into the intake where it can be drawn into the cumbustion chamber and burned. The tranny juice helps too. Less slip and better grip in the clutch packs.

JHarris1385
05/31/2007, 09:27 AM
I have NEVER changed my transmission and diff fluids before. I need to do this and dont want to pay a shop. how difficult is it and is there a how-to on here? with pics?

Dino
05/31/2007, 09:36 AM
This helped get me pointed in the right direction...

http://www.antiquecaterpillar.org/vx/Technical/4L30E_01.asp


I topped mine off the other day using this setup.

http://www.vehicross.info/gallery/data/500/thumbs/trans_fluid_IV_setup.jpg (http://www.vehicross.info/gallery/data/500/trans_fluid_IV_setup.jpg)

JHarris1385
05/31/2007, 09:45 AM
Is it just a myth when people say. You dont want to mess with your tranny much. The more the mess with it the more likely it is going to die quicker?

Not to hi jack.

But I plan to do this as well since I am getting 13.4 mpg. I plan to consider de-lifting as well.

nfpgasmask
05/31/2007, 11:35 AM
The tranny is not really that hard, but it does take some work, and its pretty messy and a little tedious. If you do it yourself, plan on starting it on a Saturday morning when you have all day to do it.

I used a little hand pump I picked up at Pep Boys to pump in the new trans fluid. I also changed my tranny filter at the same time.

I don't understand that myth, because not servicing your tranny would be more likely to cause it to croak then ignoring it. My VX was shifting like cr@p until I changed my fluid and filter and now she is smooth.

I bought my replacement OEM filter from AutoZone for like $35. It came with a cork gasket that I flattened in between 2 heavy books for 48 hours before I did the change. I would recommend doing the same if your gasket is folded, as it makes it a lot easier when it is flat.

The worse part of the tranny service is filling it up with clean fluid. Our beloved VXes have a difficult tranny to fill, to say the least, and no dipstick, so you need to follow the manuals instructions for filling, which sucks. I used Mobile-1 Synthetic Transmission Fluid. I think you need something like 4-6 quarts if I remember correctly.

Bart



Is it just a myth when people say. You dont want to mess with your tranny much. The more the mess with it the more likely it is going to die quicker?

Not to hi jack.

But I plan to do this as well since I am getting 13.4 mpg. I plan to consider de-lifting as well.

etlsport
05/31/2007, 11:51 AM
taking your VX back to stock height wont do much for your gas mileage.. switching back to stock sized tires and lightweight rims will... if your tranny is starting to go anyway, new fluid may speed up the process, new fluid may also show leaks that were already there since the new fluid will be thinner and easier to flow out small gaps

Ascinder
05/31/2007, 12:02 PM
I plan to consider de-lifting as well.
Oh no, say it aint so. Blasphemy I tell you, Blasphemy.

I agree, it's probably the tire/rim weight and size. I know when I got my rims and tires, each one seemed to weigh twice as much as the old setup. I don't think going up a few inches should hurt mileage that much, but putting stock size wheels on a VX lifted 3" or so :rolleyes: I have seen how that looks, and IMHO ;puke:

JHarris1385
05/31/2007, 12:14 PM
I have the lift ,de-lift down to an art of no more than 20 minutes. Considered de lifting during the week and lifting during the weekends for off roading. Was not sure what effect that would have on the vx?

I wish i had normaly tires to put on it. But if any of you remember I have three stockers becuase the fourth was "lost" during shipping from the seller I bought the VX from. I would heavily consider stocks for the time being.

MZ-N10
05/31/2007, 12:52 PM
for the tranny fluid, i found it was MUCH easier if u have a air compressor. just punch a hole at the top of a container and one on teh bottom. attach the compressor to the top and a rubber hose to the bottom. fill the container up and lets the air flow.....much much less tiring then pumping one of those harbor freight pumps.....

Dino
05/31/2007, 09:48 PM
Or, again... do this http://www.vehicross.info/gallery/data/500/thumbs/trans_fluid_IV_setup.jpg (http://www.vehicross.info/gallery/data/500/trans_fluid_IV_setup.jpg)

and just watch it all happen as you have a beer and keep the bottle topped off... simple. You could hang it from the mirror even, put a pan under the car. Invest in some clear plastic tubing.

The excitement of it all!!!

I'm being a nut! :p :p forgive me... :rolleyes:

Trannys are not some black art. It's just a big ol multispeed hydraulic pump that needs the fluid changed regularly or it will die!

Why? Because it needs good clean fluid to work right and lock up the clutches in each gear. It goes through a lot of heat cycles and this breaks down the fluid. As it breaks down, it doesn't perform properly and does not provide the needed pressures to actuate the mechanism that locks up the clutch pacs. This robs mileage, causes the clutches slip, and heats up the fluid even more. Parts of the clutches and the steel plates in between them begin to flake off and further contaminate the fluid and plug up the filter. The problem just gets worse from there and before you know it, you need a new tranny.

Keep that trans serviced!!!!

JHarris1385
06/04/2007, 06:56 AM
I am going to do the tranny and diffs this weekend. This will be my first time doing these two things. Is there a check list on here that I am missing of what all is needed to perform this task?


Ascinder what is your mpg, since you are one of the highest lifted vx's?

BeeVenom
06/04/2007, 04:04 PM
I bought Don DiBart's 01VX a couple years ago (long time V-Cross member) and one thing he stressed was the transmission flush and refill. He just did a trans flush prior to me purchasing with synthetic fluids and i intend to follow the same process. I will flush/change at 60,000 miles and continue for as long as we own the VX. All fluids in my VX are synthetic and i think it's worth the extra expense. These transmissions can be finicky and the flush/refill process even with synthetics is cheap insurance for having a long-lasting transmission. I've had no complaints and still love the Proton as i did the first day i purchased it.

BeeVenom
06/04/2007, 04:42 PM
P.S.
I'm running ALL SYNTHETICS including engine, transmission/transfer/differential, plus brake fluid and power steering. Again, I think it's a good insurance policy against future potential problems/challenges. One thing i will add is that I've always used Castrol synthetics (i've owned a bunch of british cars.....Castrol is the 'Thing' with british). However, i found through news updates (and publicized law-suits) that Castrol started using petroleum-based stocks in their synthetic oil to cut costs a few years ago which meant that they were NOT really 100% 'synthetic' any more in the true sense of the word.
If you use synthetic engine oil make sure it is a 'Group 4' synthetic and NOT 'Goup 3' synthetic OR less.
Mobil 1 'extended service' is a 'group 4' oil (Red Line and some others are too, but i have not used them). I am now using Mobil 1 Ext. Service.....for what it's worth. If you change every 2000-3000 miles, it may not be a big deal. I do change at 2500 miles but I still use 'Group 4' oil.
Needless to say, i do believe in synthetics for mileage increases and longevity although sometimes you may think it's too expensive. I think NOT!
I do get 16-17 average (even with an Alpine Superchager w/7 psi boost) and have hit as high as 23 mpg on highway with average 60-65 speeds.
Synthetic is the way to go!

JHarris1385
06/05/2007, 11:09 AM
Or clean,replace, service your Fuel Pressure Regulator. I have seen a 3-4 avg mpg increase since.

JHarris1385
06/05/2007, 11:12 AM
What are the group four oils?

tom4bren
06/07/2007, 06:02 AM
One thing to keep in mind about gas mileage right now is that we are now running on summer blend gasoline. Summer blend has about 10% less energy content so your gas mileage will probably be 10% lower as well (maybe more). Isn't it nice how they've set it up where the more expensive gas gives us less performance?