V8 Lover looking for better MPG's
 

We'll its true I am a V8 lover, gotta love that big block torque !
My DD is a pick up. Its an 08 Silverado 4.3 WT. Pretty happy with it but its a shame the little engine gets worse MPG's than the V8's I understand lots of factors involved. Couldn't afford the LS V8's so moot point.
I have yet (but I will !) get 20 MPG in the silly thing.
I am sure your web site will help ! Not interested in driving in any way that may upset or endanger anyone else.

So my first step is;
* Synthetic oil and I hope it helps but wont be upset if it does'nt.

*Looking at my mirrors and thinking :D

*Thinking about a bed cover/canopy mod (went through 27 pages of that canopy thread *awesome*)

My truck sits azz high and have heard that lowering it to level has helped
others?

Wouldn't mind turbocharging someday, have heard the fuel economy is there
if you can keep your foot out of it.

Have lots of questions but I'll save them till I've searched more.

Hi and welcome to EM!

You know, depending on your particular vehicle usage, there are times when owning a fuel sipper as a DD as well as a full size truck for towing or specific tasks makes financial sense.

In any way, got luck with your goals!

You love V8's, and you bought a V6? C'mon now.

First suggestion, buy a smaller car if you can. Second suggestion, depending on how long your commute it, but a bike. Third suggestion, ecomod your car.

shoulda got the LS one... I did :D anyway welcome! I'm new too

I understand in fact I bought a 2004 Kia Rio a number of years ago because
the fuel, insurance AND car payment were less than the fuel in my 11 MPG
Ford Bronco.

V6 vs. V8 ...........about 9 thousand dollars more IIRC . I tow a utility trailer now and then and maybe a small travel trailer in the future.
Oh and for my V8 fix my 425 powered 65 cutlass is getting a 500 ft lb. 455
soon. :thumbup:
Smaller car ? actually have them already one is a 05 Scion XB best yet 37 mpg., avg. about 32 with me driving about 30 with my wife.Its going away because we are bored with it. In its place will be a 1980 Volvo Bertone cp.
powered by a 2000 ford Explorer 5.0 and atm 4 sp. should get better than the old V6 Volvo. My goal is 28 freeway and who gives a crap around town :cool:

Also have a 66 Volvo Amazon wagon which may see some time as a driver when its deemed reliable enough.

The parts car for the 66 is a 68 Amazon wagon and I could see modding that for 40 MPG or ?

Back to why I am here (the truck right now) it gets about 18 mpg with my rush hour drive. Just shy of 20 @ 70 mph.


Love my truck, going to have it for my DD for a couple years and WILL improve it MPG'S

Looking forward to learning from you all !

THe volvo has some serious road potential. Overdrive tranny, 2.78 rear ratio, slightly taller tires...... That Ford v8 will be at 1600RPM at 60. Do a blocked grill and full underbelly......bet you could be at 32+ on the road!!!!

I have an 02 Q45 that I'm shooting for 33 on the road. Pretty much there with grille block and full under body pan.

umm Good idea with those silverados SLOW DOWN that'll increase it just in itself stay at 60-65 instead of 70-80 on the highway. Lowering it will definately help A turbo would make that truck very fun and also it would save quite a bit of gas. make sure your tires are filled porperly and definately get some kinda cover for the bed

no

Agreed. A carefully tuned supercharger or turbo might help, but forced induction + larger displacement (with "fun" added to the equation) only spells more fuel.

The WT has the most potential of the Chevy lineup with stripped-down options (less weight), V-6, and I'm guessing a manual trans.

Modding and driving efficiently for highway speeds and using momentum to your advantage could yield results.

Stick with it and see what happens :thumbup:

RH77

Is this a fact? EPA ratings?

Welcome to the site. There's lots you can do to the truck & your driving to improve.

That's what i meant a tuned turbo setup running between 3-6 Psi might help

Something like an STS rear turbo mount or another brand if it would work better . Don't really know the difference between them

By fun u just meant a little more power when you really wanted to open it up sorry if i was unclear about that

Usually the bigger engine in trucks are geared lower and allow the big torquey engine to turn slower and makes for better MPG than a slighter lower geared smaller engine.

Care to explain how this would work? I've never heard of a supercharger especially increasing FE.

Get the biggest block heater you can find, this helps in faster warm ups. Make sure the tune-up parts are good. Make sure the thermostat is the correct temp. You can loose 2 mpg or more if your eng. is running 175* instead of 195* oem range. I run a 205* t-stat year round, there not avaliable for all engines though. Remove unnesesary weight, I see alot of people haulling a bunch of stuff around thats usless. When the engine is cool take it easy on the gas, efi engines dont have chokes so the injectors flow alot more fuel durning cold operation. Hope this helps ya.

Slow down. I had an Astro van with the 4.3 V-6. It got 15-17 mpg at 70 mph, but 22 mpg at 62 mph.

Thinking out loud...

In theory it might work like a mild turbo, by offering additional power at lower RPMs. In this case, taller gearing / final drive would be required (and some sort of ability to regulate the boost). The thought of a supercharger for engines of higher displacement comes to mind instead of a turbo (except for Diesels). I recall hearing of a zero-boost CRX a few years ago that yielded exceptional FE. The SC could be flawed logic...

Thinking more about it, the parasitic drag of a belt-driven device may not offset the gains. Luckily, easier methods are available to start with first :)

RH77

Dang, those trucks sit high... looks 4-6 inches taller than my '03.

When you wear down your tires, look at ditching the steelies and getting some smoother, lighter, aluminum wheels. Lots of stock take offs that you can find on craigslist cheap, usually with tires.

Slow down. Buy an Ultragauge.

I also coast in Neutral which seems to help.

for '08, the EPA rates the 4.3L V6 the same as the 5.3L V8 (15/20) which is slightly better than the middle choice of a 4.8L V8 (14/19). These trucks are pretty heavy though... 4400+ for the lightest version.

GM (Ford and Dodge too) no longer offers manuals in their 1500 series trucks. I think '06 was the last year it was available, and even then they were rare. I searched for months trying to find one before I gave up.

Mike

welcome to em
appears to me your more of a gearhead then a modder (your not alone )
the best think i can recommend is slow down a bit set your cruz speed at 60 i think you will have more money to put in the old cutlass

Yes I am a gearhead 1st! No issues there. However I drive smoothly and calmly. I do try (and with a fair amount of effort) to get the best mpg I can.
I've been a slacker about doing anything to my truck.
Many other projects. Been using Mobile 1 oil 0w-30 and it seemed to make no difference. No surprise. I'm torn between leveling the truck(lowering the back 2-3" or complete lower. Thats another item that won't upset me if it shows no big gain. Getting too old to jump off the tailgate of this thing, it sits so high. From what I've researched its probably not a good engine to supercharge due to the limited EFI system. I swear the V8's got a mile or two better than the six but maybe I was wrong?
Either way Its been almost 3 years as a daily driver and I'm getting about 18
avg. Yet to see a 20mpg tank and boy have I tried.
Now its winter and I just installed winter tires and my mileage has dropped to high 17's Had a few high 19's. Was hopping for a 20 before any mods but what the hey.
Thanks for the reply's:thumbup:

maybe a new air filter and air inlet like those little riceburners run

Wow they still used the 4.3 in 2008? That has to be close to 25 years or so for that engine.

Definitely slow down. If you stayed at 55-60 no doubt you would have 20 mpg. Lowering would help a lot too, that thing is all jacked up.

I've gotten 22mpg with an Auto 5.2 v8 dodge 1500, trust me, If I can do it in that thing you can definately do it in your infinately better GM.

If its a 2wd put small tires on the front end (I did with my dodge and it really helped, I think the loss of height was the reason that and they were LRR)

Things I have been considering are
1. Aero topper
2. Plenum gasket (shouldn't apply to you)
3. MT swap

I would estimate the best thing you could do would be an MT swap, it takes patience but remember the 700r4 and NV3500 were the same dimensions and XMBR wise, I would estimate with a bit of visual inspection you would find your XMSN and a MT counterpart might be drop in replacements.

I am right now waiting on getting me 89 diesel sub converted to double overdrive MT. I will actually need grandma gear to take off.

Something else you can do but everybody here hates is to reprogram the ECU the hard way using some of the freeware ECM utilities and move your maps past stoich in your highway cruise region (if you cruise on the highway a fair amount) thats good for about 2-4mpg in of itself. You need a good bit of tuning knowledge and patience to pull it off properly though.

Just make sure you can flop back and forth.

Good Luck
Ryan

What's the scoop on this freeware ECU tuning?

I've looked at a service to reprogram the ECU for my '03 Silverado. One that caught my eye claims 1-3mpg improvement (Not much on a Prius, huge on a full size truck). The thing that has stopped me is cost. $200+ for a mod that may or may not improve efficiency. A free utility to play with sounds interesting, but you still need a ECU -> PC interface of some sort...

Mike

You are more or less completely and utterly on your own is the scoop.

Those services may or may not work and the price is obviously not very good.

The megasquirt and other options that are controlled by you are also not real cheap.

If you do it yourself completely you need to understand the binary portion of the rom, how to make it into a human readable thing, how to identify its parts and how to modify it.

Generally you will also need a computer, a soldering/desoldering iron, nerves of steel *******izing and putting a socket in your ECM and a ROM reader for the PC.

I failed when I tried that route so I am little help, also remember each vehicle and motor varient has its own club and potential utilities, a google search might help.

Oh and if you do it yourself it voids any warranty you may have.

Cheers
Ryan

if you are gonna spend the money on a synthetic oil go with amsoil....dollar for dollar the best oil out there

Here is a site I used for some of my initial ideas for FE improvement:
A Truck That Drinks Less Than a Car? | Popular Science
Just doing the panels outlined in this article will benefit you. I am, and can get 20 mpg nearly at will once the truck hits 4th gear. My truck is rated 14/19.
Make sure your front end alignment is correct. I discovered mine has been out of whack for a year?! Boy is that frustrating.
Lowering your truck will also help, but not dramatically. It does reduce the drag coefficient. Synthetics also help, but the kicker is reducing your truck's Cd. Speed (velocity) is the enemy, as drag increases with speed squared, not just directly with speed. See the drag equation, rearranged to solve for your Cd:
The Drag Coefficient
Drag = (1/2)*Rho*Cd*A*V*V where Rho (I don't have the greek letter key) is air density, Cd is your drag coefficient, A is your frontal area, and V is your speed (or velocity).
The factors you can really change are your speed/velocity and Cd.
As you can see, the faster we go the drag increases dramatically. My truck has a 0.52 Cd, and with 32 sq ft of frontal area (A), I am in a world of hurt for drag. I suspect your truck isn't that much better than mine.
Here's another page to look at: Drag Force Calculation and Equations. Drag Coefficients.

[edit] rmay, when my alignment was on track I hit 24 mpg driving across northern Utah on I-80, so I agree, GMs are typically better on aero than Dodges, especially my Gen3. GM has an aeronautical engineer working high in their company, so I am sure he is influencing things...

Re: that Pop Sci bit: Wow. Just... wow. Aside from the pickup aero info (good), their "test" and their premise is complete crap. :(

Word.
 

Agreed -- the repeatability and summary is just, well, weak.

Further, people don't drive completely on the highway and park it, there's a little thing called mass and a concept known as acceleration. I implore the author to investigate further :turtle:

RH77

Hrmm... Not at all concerned about warranty. I've never owned something with a warranty.

I'm a little light on nerves of steel when dealing with modifying the code in an ECU and with soldering electronics. I'm sure I could do it, I just don't have the experience to make sure my custom tune doesn't burn a hole in a piston.

I *may* still bite the bullet and give a reprogrammed ECU a try, but probably not a DIY on this mod.

Mike

I would look at the intake setup. Warm air, particularly in winter, will probably help.
A cat back exhaust, or at least a lower restriction muffler should help exhaust breathe better, plus play to your gearhead side (I am one too).
This vehicle swallows a BIG lowering kit with ease. I have seen 5/7 drops that look like a 2/3 on an 88-98 CK truck. Get it down.

There are aftermarket hand help programmers that adjust fuel curves and timing. There are also programs out there (EFI LIVE, LSI Edit) that allow you to modify many parameters within the computer code itself.

I think much of your benefit is in the computer controls. A full size truck with a 4.3 was obviously presumed by GM to be a work mule. Since they presume the truck is going to be loaded down and driven many miles, they were probably VERY conservative with the tune. An aggressive tune will have leaner fuel and more timing, but this type of tune could prove disasterous in terms of warranty for GM, when the local (insert large fleet business here) runs these trucks all over hell and back, with crap gas, no maintenance, and drivers who probably don't care about the truck (company trucks)

As such I bet GM has these trucks tuned with conservative timing maps, and too rich fuel maps, to prevent lean conditions where Phone Company Phil pings the motor to death, and GM has to warranty it.

Is Amsoil cheaper or something?