Best Single MPG Mod?

[ygmn]

gas weighs a lot especially a full tank if you don't drive far every day just keep the tank half full or even just above a quarter tank, it  got me a little better mileage

gas weighs about 6-7lbs per gallon I forget actual number but is less then water @ 8 lbs per gallon...

so 15 gallons which is half a tank = using 7 lbs = 105 lbs...

Which for the 6000 pound truck is not very much... I bet it effects the mpg less then 0.01%

the best way tpo get better mpg... is to take off very very very slowly.... from stops.. as that is where the majority of the fuel is wastd getting this pig of a truck moving....
 
also anything ovr 50 mph is wasting huge amounts of fuel fighting the wind..

[PerfectReign]

gas weighs about 6-7lbs per gallon I forget actual number but is less then water @ 8 lbs per gallon...

so 15 gallons which is half a tank = using 7 lbs = 105 lbs...

Yes, gas is roughly 6lbs / gallon. I know jet fuel is a little more at 7 lbs./gal.  (I used to be a sub-contractor working at an Air Force base, so we'd calculate these things.)

Which for the 6000 pound truck is not very much... I bet it effects the mpg less then 0.01%

My thoughts, exactly.  6 lbs * 26 gal = 156 lbs. 

If this were a Yugo, I'm sure that 156 lbs. would have a drastic effect. On an Avalanche - not so much.

the best way tpo get better mpg... is to take off very very very slowly.... from stops.. as that is where the majority of the fuel is wastd getting this pig of a truck moving....

I remember Sperry mentioning that he tried to keep his truck under 2000 rpm. Not sure how he did it where he lived but I do the same. For most of my drive, I can keep the truck under 2000 rpm, even on starts. That really helps out.

also anything ovr 50 mph is wasting huge amounts of fuel fighting the wind..

But it sure helps when you have an 18-wheeler on your tail!

[LornesAV]

Don't mean to  but it's related to your question. The AV has now quit down shifting on hills and some were fairly small and milage is improving with 93 octane still not sure about the ethanol.

[Z66Modder]

Tune it for 91 or 93 octane gas (which ever is available) and always fill it with that. The MPGs and added power will justify the higher priced fuel.

[LornesAV]

Loss of mileage is for me related to oil loss again 
So I wake up to a check engine light this morning stop by auto zone number 7 misfire. Same thing I had last time. I have already scheduled a test for this next week. I plan to make a poll here to see who has had this is who hasn't. What milage apprx did it start? Has it reoccurred? If you don't have the is what do you typically dive city or highway and how many miles?
If I can't get a resolution a lawyer will be spoken to.

[Joelg1980]

gas weighs a lot especially a full tank if you don't drive far every day just keep the tank half full or even just above a quarter tank, it  got me a little better mileage

That's intersting. I've heard that having the truck less then 1/2 full will cause it to use more gas, which as I'm typing this makes utterly no sense to me now. I just got 16.8 from my 2004 with some rather agressive driving. I'm a teacher and I've been really agitated after school Can't  the students, so I took it out on my gas pedal and really  this last tank. I also had to put 31 gallons into it and was terrified I wouldn't make it a gas station, but I did.

[LornesAV]

Tune it for 91 or 93 octane gas (which ever is available) and always fill it with that. The MPGs and added power will justify the higher priced fuel.

So I am planning on the diablo that just went up for sale on this site. If I tune to 93 (only 93 or 87 available) will there be issues when only 91 is available?

[Crashz71]

Why not use neutral down long hills? Out of my drive, I can coast for 6.3 miles. Adjusting RPMs before engaging tranny, what does it hurt?

This actually uses more gas than if you just let it coast in gear...just saying.

[Carpenter29]

I get better mileage when I use premium fuel. So I always try to put premium in it.

[AvyOwner23]

I saw on top gear that coasting at speeds uses almost no fuel in modern cars, because the spinning of the tranny keeps it running while using less fuel. Don't know how true it is but I thought it was interesting.

[hauselvaughn1]

That's intersting. I've heard that having the truck less then 1/2 full will cause it to use more gas, which as I'm typing this makes utterly no sense to me now. I just got 16.8 from my 2004 with some rather agressive driving. I'm a teacher and I've been really agitated after school Can't  the students, so I took it out on my gas pedal and really  this last tank. I also had to put 31 gallons into it and was terrified I wouldn't make it a gas station, but I did.

As an engineer, I know where this comes from.... And in older cars, yes this is somewhat true. In an older car, the fuel systems were very, I mean VERY basic. They were actually exactly what you would imagine in your head right now. A simple fuel tank with a spout, or filler hose, that led up to an accessible hole where fuel could be added. In this gas tank was a basic fuel pump, which was somewhat easily accessible for a reason (always had to be replaced). Things were even worse before EFI came about. Anyways, back on topic. Fuel tends to evaporate relatively quick. Therefore, this claim has to do with the rate the fuel would actually evaporate from the tank whether it was actually in use, or just sitting over night. A smaller amount of fuel (i.e. 1/4 tank would obviously evaporate faster than a full tank, due to surface area etc). New cars have a lot more advanced fuel systems. They eliminated nearly all the evaporation issues (from the little flap on the filler spout to advanced gas caps, circulation hoses .. the list goes on).  But thats how that theory began and people have tended to continue believing it.  Trust me, you waste more money by making more frequent stops to refuel due to only filling up halfway, rather than filling up and not having to stop as often.

[hauselvaughn1]

I apologize, I just re-read what I wrote and it probably doesn't make sense to some.   People used to think that a way to reduce loss due to evaporation would be to keep the tank full, which reduced the amount (volume) of space above the liquid (gasoline) in the tank.

[SmokeyJoe]

I apologize, I just re-read what I wrote and it probably doesn't make sense to some.   People used to think that a way to reduce loss due to evaporation would be to keep the tank full, which reduced the amount (volume) of space above the liquid (gasoline) in the tank.

I'm kind of an old school engineer too and I remember when we kept the tank full not because of evaporation but because of condensation. 

The theory was that when the tank had air space in it, the air contains water (humidity) and if the temperature changes then the condensation (translate water) would sink to the bottom of the tank and then on into the engine. the other theory was that it would also rust the tank bottom (I don't see that oxidizing effect happening when there is no oxygen under the fluid however).

There still may be some truth in this condensation theory today but with the complexity of the modern vehicles, I would think this would far down the list of things that could go wrong.

[wyotonka]

i know if im on my "budget tanks" where i am trying to save fuel i will adjust my pedals all the way forward... flooring it isnt near the same that way it cuts the acceleration down greatly

[adamjeeps]

If you can draft off of a big rig, it saves a ton of gas. I'm not saying its safe but it does work. And the truck driver probably wont like it

[we_fly_high]

Best MOD I would say is a custom tune.

[Ranger50]

I saw on top gear that coasting at speeds uses almost no fuel in modern cars, because the spinning of the tranny keeps it running while using less fuel. Don't know how true it is but I thought it was interesting.

The way the maps are written, high vacuum, no load, idle-ish TPS readings=no fuel. You end up with a giant air exchanger. They keep the converter locked in D and OD to maintain the pumping action.

[TomShepard]

Remove or reduce unnecessary weight.

[mavericknj]

You could try the UPS method - Adjust your routes so that you make alot of right turns and avoid stopping at traffic signals and left hand turns.

Seriously, there is no mod or upgrade that is going to improve your mpg drastically. Many of us are happy at 15-16 city and 19-21 hwy. Anything above that is a fantasy.  Depending on your wallet, driving habits and type of daily commute will determine your mpg. Do your research, upgrade the air filter to a K&N, upgrade your plugs to iridium, clean your MAF sensor, buy a tuner, change tires to city/hwy rated tires, drop the spare (keep the slime kit in the tool box), use fuel system cleaner with each tank fill up, change your oil every 3k, cut your vehicle warm-up time, etc. http://[b]It's 7200 lb aerodynamic Brick. Built for those who love the option of fun and versatile daily hauler with room for 5 or full size drywall panels. Excellent towing capcity for our weekend toys and enough to enjoy a day off-roading.[/b]

The wife and kids love it because of the styling, versatility and modifications for a day at the beach, in mountains, antique shopping, moving friends or a night on the town. Inaddition, they don't have to worry about filling up the tank, I do.

Enjoy the vehicle for what it was designed for and not it's limitations.