Best Single MPG Mod?

[Oleksy]

What's the best single mod to improve gas mileage?

I was going to order a cold air intake, but after doing a lot of surfing, this doesn't look like the best mod to improve gas mileage.  Would a Superchip programmer be better?

[MyBigToy]

Buy a 4-cylinder car! Sorry, I couldn't resist.

From my experience you won't improve your mileage much along the way when you start modding. If I was going to pick one mod it would probably be a programming suite like HPTuners or EFI Live. They aren't cheap but they give you complete control over adjusting your pcm and tcm. If you aren't up to lots of reading and learning neither one of these programs is for you. Next on the list, I guess I would try either  dyno tune or mail order tune, making sure I explained to the tuner that my goals were greater mpg. Next would be a canned programmer but they are limited in the amount of adjustments you can make.

Realistically, you need to do something to the pcm, the intake, and the exhaust to see the full effects. You have to be able to pull more air in and remove air out more efficiently. You can do a drop-in K&N filter for the stock airbox pretty cheaply and it will gain you probably 80% of the benefits of a CAI.

[ltxi]

Best single mod in my opinion is a competent, tailored tune. Second, depending on your existing shoes, may well be a carefully chosen, new set of tires.

[Hugz]

As easy as it sounds, and VERY hard to do for a lot of people..  Go the speed limit..  It makes a HUGE difference, that and like i was brught up before the size of you rims etc makes a big difference.  I went back to my stock setup and gained between 2 and 3 MPG..

Good luck.. 

[ltxi]

As easy as it sounds, and VERY hard to do for a lot of people..  Go the speed limit..  It makes a HUGE difference, that and like i was brught up before the size of you rims etc makes a big difference.  I went back to my stock setup and gained between 2 and 3 MPG..

Good luck.. 

Good concept, but as you point out, sometimes hard to do. And even then....truck gets great mileage at around 65, not quite as good at 70, really starts to fall off at/after 75. Twenty miles of my 25 mile one way commute is in free flowing, 75 mph speed limit, traffic. Eighty is the norm and under 75 you'll get run over/are clogging up the flow.

[chAVey]

Sorry to say, but reality is the stock system is probably the best for MPG.  Yes, programmers, etc can get slightly better MPG, but I don't think you'ld really earn your money back.  I have a CAI, Dual Exhaust, and programmer and my MPG is way WORSE than stock.  I got the Edge Evolution Programmer and it acts as a gauge cluster while running.  I can tell you that avg MPG is MUCH better at 55 than 75.  But I know it's hard to stay off the pedal when you hear that throaty roar!

[ygmn]

brick under gas pedal....

[MooseAlanche]

brick under gas pedal....

And an egg on top of the gas pedal 

[BCmountaineer]

Rig up a SAIL panel... heheheuhuhuheheh...

[MyBigToy]

Sorry to say, but reality is the stock system is probably the best for MPG.  Yes, programmers, etc can get slightly better MPG, but I don't think you'ld really earn your money back.  I have a CAI, Dual Exhaust, and programmer and my MPG is way WORSE than stock.  I got the Edge Evolution Programmer and it acts as a gauge cluster while running.  I can tell you that avg MPG is MUCH better at 55 than 75.  But I know it's hard to stay off the pedal when you hear that throaty roar!

With something like a Predator programmer or a tuning suite like HPTuners it's pretty easy to fix. If you're really serious you could set the speed limiter to, say, 70 mph. You couldn't go any faster than that. It's probably not a good idea but if you really wanted to you could.

[chAVey]

True.  But I think that's the point of programmers - I don't WANT to limit it.

[Oleksy]

Thanks for the input.  I do tend to drive like an old lady, and coast a lot, but I'll still like to get better MPG.

If the CAI negatively impact MPG, would a drop in result in lost mpg too?  I'd be willing to go the drop in route ...

Also, I'll look at a programer.

[MS03 2500]

I have to ask what kind of mileage are you getting now.

[Hugz]

Good concept, but as you point out, sometimes hard to do. And even then....truck gets great mileage at around 65, not quite as good at 70, really starts to fall off at/after 75. Twenty miles of my 25 mile one way commute is in free flowing, 75 mph speed limit, traffic. Eighty is the norm and under 75 you'll get run over/are clogging up the flow.

But its much harder to run over an avalanche.. 
 Same here on the LONG commute as I am at 33 miles..  But I also knew that keeping the av was going to create a higher gas bill each month..

[ygmn]

Buy another car and only use Avy when you need it...

[PerfectReign]

Buy another car and only use Avy when you need it...

Looked into that. Way too expensive.  Even with a 100% increase in mileage (30 mpg), your second car/truck/motorcycle is going to run more because of insurance and general maintenance.  I seriously thought of this for my 20-mile commute, but dropped it because it just wasn't worth it.  After my dad passed away, I even drove his sub-compact Chrysler Sebring for a few months. It was a PITA to try and coordinate when I'd need the AV (for baseball crap for my kids) and not.  After a month or so, I decided to simply sell it.  The extra gas mileage wasn't worth the insurance cost or feeling like I was a sardine.

I vote for the brick idea!

[avalonandl]

Thanks for the input.  I do tend to drive like an old lady, and coast a lot, but I'll still like to get better MPG.

If the CAI negatively impact MPG, would a drop in result in lost mpg too?  I'd be willing to go the drop in route ...

Also, I'll look at a programer.

A dyno tune with the emphasis on economy will be yyour best bet. A programer will do the same but a dyno tune has more parameters to adjust.

Avalon

[Oleksy]

Right now, with a mix of driving, I'm getting 15.9.  I have made a few trips pulling my light boat, which lowered the mileage.

Of course, I'd like to get a little more....

[chevyguy83]

So I was really interested in increasing my MPG and PowerBlockTV had a special they did on a mid 90 Dodge Ram 1500 with lifted tires.  I have started to do much of what they tested and it does work.  I don't know all of them but this is what I have done and intend on doing in the future to increase the MPG of my 03 Avalanche 1500.  When I started the quest for better gas milage I was high 10's low 11's on a weekly basis.  Without changing my driving I am now at high 15's and that is not highway driving.  Highway I have been upwards of 20 MPG. 

1. BIGGEST PAYOFF- buy a computer programmer.  I have a hypertec and it increased my milage 2-3 mpg.  It does cost but if you look at it like this, after you re-coupe the savings of the cost of gas, you will then be saving money.  Mine cost around $300 and I bought it a few months ago.

2. CAI- Just with that I was able to get another 0.5 MPG out of it, don't need to buy an expensive AFE, I have had one of those on a 05 GMC and it was great, bought a cheap on on other cars... just a good.  The one I have on the AVE is a ebay special.  I love it.

3. Make sure your vehicle is tuned up and maintenance is done. i.e. tire pressure, good oil....

TO BE DONE:
1.  Change out the mechanical cooling fan for an electric cooling fan.  Cost is about $100, only a few wires and then you get around 2 MPG. 

2. Make sure that there isn't any extra weight on the vehicle that isn't needed.  i.e. loading straps, oversized spare tire, junk, toolboxes that aren't needed, additional hitches... just make sure you don't have a bunch of crap that doesn't need to be riding around costing you MPG.

3.  Driving style is a big deal, PowerBlock TV installed a vacuum gauge in order to help control the gas pedal, shutting off your vehicle doesn't help t stop lights, and definitely don't shift to neutral going down hill.

4

[PerfectReign]

those are all good tips.

What if you buy a 60 MPG Toyota Prius and put that in the bed?

[misura]

 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?

[ygmn]

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?

transmission.

[LornesAV]

I tried shell v power lowest octane without realize it before my research and got better mileage. I viewed this site and found ethanol free gas and got better milelage with considerable city driving. 2-3 mpg estimated,I typically get less than 16 with very much city driving and driving highway 55 in Missouri I get 16 or less. Last tank 17.4 including that city driving. http://www.pure-gas.org/extensions/map.html

I filled up today with shell v power 93 octane and I will let you know how that goes. $.24 more per gallon. It was not marked no ethanol.

I have a rough idol and I hope it clears that up, on other sites there have been some great increase with the 4 cylinder engines.

Here is a site that help you track your mileage   http://www.Fuelly.com/car/

[LornesAV]

18.5 on the way back from Cape Girardeau mo. 93 octane not sure about the ethanol in the gas or not. I will finish the tank tomorrow or thursday to see what the DIC  calculates. Highway 70 is usually by best mileage unless the head wind is high.

[stogen]

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

[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.