Can transmission condition effect MPG?

[pastadog]

Hi guys!

So for another fun question :LOL2:.... Can an automatic tranny effect my MPG's on my 3y? Reason I ask is I checked the tans fluid and there was plenty and I have the ever so popular jump when going into reverse, drive and 2nd gear. I'm kind of thinking about changing the Trans fluid and adding some lucas trans fix..... What do you guys think? Can this help in anyway..... better MPG..... a little more power?

Also, if I do change the trans fluid should I go ahead and have them change the diff fluid as well? :dance2:

Thanks friends!

[pastadog]

Anybody? I know it's probably a dumb question but would like to be sure.... Thanks

[Wonderwagon]

I doubt fuel economy will be improved, but if your tranny is kicking, changing the fluid and adding Lucas should smooth it out and keep it alive a little longer. Remember that too much transmission fluid is bad too, so after refilling drive it around and shift through all the gears and then check to make sure the fluid level is in the "warm" range on the dipstick.
Changing the rear diff fluid is easy, just unbolt the bottom plug to drain and refill until it is up to the level of the top plug.

[pastadog]

Oh ok perfect! Thanks

[llamavan]

Changing the rear diff fluid is easy, just unbolt the bottom plug to drain and refill until it is up to the level of the top plug.

Actually, the easier way is to remove the fill (top) plug FIRST and then proceed as above. If the fill plug is frozen and the fluid has already been drained ... :yikes:

Gwen

[pastadog]

Sneaky sneaky!! Very good point :clap:

So can a freshly filled diff help out in anyway with MPG's? The reason I'm trying to get better MPG's is because I'm only getting around 220 a tank!!! I have a fresh o2 sensor and pretty sure a pretty fresh tune up and I've ran Lucas fuel treatment cleaner three times in like 10 fill up's..... I have no other clue what it could be :( It's totally gonna make me cry!:roflmao: I just want at least around 300 like most of you, I mean it is a 4cyl Toyota and pretty light!

[llamavan]

Changing the diff oil is vastly more crucial to keeping your diff than anything else (and that is plenty important all by itself). Likely you won't see any noticeable improvement in MPG.

My vans' e-light comes on at different levels; my '84 used to come on after only 10 gallons, for instance, and my '89 4WD is currently coming on after using close to 13 gallons ... so "xxx miles per tank" really doesn't tell me (or you) very much. What's the actual MPG your van is getting, and how much of that is highway and freeway driving (not freeway parking or freeway creeping!)?

Gwen

[pastadog]

Ha Ha I think my E-light comes on early as well bc every time i refill I put in usually 10-12 gallons. Weird.

So for my billionth dumb question.... what is the easiest way to calculate MPG's because I'm taking nudE on a trip tomorrow night and will do it :dance2:

Thanks Thanks Thanks

[llamavan]

(1) Reset the trip odometer when you fill up (and do fill it, but no top off). Make sure it's actually registering as you pull away — guess how I know this.

(2) Next time you fill up (again, don't top it off), write the trip odometer results on the receipt and reset the trip odo again.

(3) Do the math (miles driven divided by gallons that went in the tank = MPG).

(4) Keep records, including any unusual events (trip that included going up steep grades or the reverse, getting caught in a traffic jam, etc) that can alter the fuel consumption one way OR the other.

Now you have an accurate MPG picture, and an idea of whether your van needs work or not ... as well as an inside track to when your van is just starting to get sick, :yes: or just when your formerly favorite gas station starts to sell you crap. :nono:

Gwen

[timsrv]

:LOLabv: Simple math. Miles divided by gallons. 220 divided by 10 = 22mpg :no:

[llamavan]

But 220 divided by 12.5 = 17.6. Unacceptable, IMO, no matter what your driving conditions and habits. OTOH, 22 mpg for an A/T van with a fairly high percentage of stop-and-go driving would be pretty darned good. 22 mpg on the highway leaves room for improvement.

The above three possibilities for "220 to a tank" illustrate how important it is to have facts and figures, not just general impressions.

Gwen

[timsrv]

Ha Ha, looks like we posted at the same time. Another thing to help keep your figures as accurate as possible would be to use the same pump with your van parked the same way (irregularities in the pump shut-off and the levelness of the surface can throw off the amount of gas your van takes). Also fill using the same technique. If you use the auto shut-off on the pump (recommended), be sure to use it the same way for the next fill-up. If you top off by hand, try to get the same level the next time. Topping off isn't such a great idea, but can help you match the same level as you had before. Only do it if you are immediately driving the van on a trip.......like for over 10 miles and the outside temperatures aren't expected to rise much.

Just remember that gasoline expands when ambient temperatures rise, so topping off can be dangerous if you park it in the sun without burning much gas. You might return later to find a puddle of gas under your van. So use your brain......safety 1st. Tim

[timsrv]

BTW, my van has a ladder rack, an awning, and 3,000 lbs of cargo. In addition, I aways floor my van for take-offs and don't let up until I'm doing the speed limit (or some slow poke gets in my way). I also pull a small covered cargo trailer at times (that's often overloaded as well) :dizzy:. I think all things considered, in my case 17 - 18 mpg's is pretty decent. In your case, it's probably not. Tim

PS: When calculating mpg's, more statistics = more accuracy. Check it for 3 tanks in a row and average out the results. If you don't like it, try getting gas some place else and try again. Like Llama said, crap gas = crap mileage.

Here's a related thread: http://www.toyotavantech.com/forum/showthread.php?349-Tire-size-and-fuel-mileage

[pastadog]

Awesome.... I'll start today! :slap: