Fuel Economy and $4 gas...

[clean71]

I don't normally like to put crap in my engine that says it does xyz. However, when I went to visit my parents in MT a few weeks ago, I met their neighbor, a very nice German lady who got the shaft by her husband and has been doing whatever she can to make ends meet. Anyway, long story short, she gave me a product to try that seems to work quite well. My DD is an '05 Nissan Titan that has gotten a high of 13-14 MPG since I've had it. The product she gave me is a fuel additive that is supposed to help the fuel burn more completely. I used it on my return trip from MT to AZ and recorded my mileage for the entire trip. Product was added 1/2oz at each fill up for three tanks and 1/4 after that. My average speed was 75-80MPH. Results were:

1st tank: 13.29MPG
2nd tank: 13.46MPG
3rd tank: 14.72MPG
4th tank: 17.4MPG
5th tank(some of this was around town driving when I got back): 16.5MPG

I made no changes in my driving habits and have continued to get above 16MPG for my daily 10 mile commute. Considering that I was averaging around 12MPG before, it's a nice litle change.

My dad has been getting between 35-40MPG in his Subaru Outback with this product.

This may or may not be for you but if interested, PM me. The company that she works for is an MLM. I have no financial interest in this whatsoever, but I'd rather give you her information via PM and ask that if you decide to buy the product, that you buy through her.

Long story short, her family owned a large department store chain in Germany. She inherited a couple million dollars, married an American guy who moved her to BFE in MT (I think everywhere in MT is BFE isn't it?) and subsequently squandered her money and left. My parents help her as much as they can and she works her but off to pay her bills and eat. So, anything you can do to help would be great.

If anyone has a problem with this post, I'll delete. Just think it seems to be a decent product and it would help my parent's friend out. If you PM, I'll give you her number and you can call her, talk to her, and make your own determination.

[screwballl]

a few things I did with my 76 truck and 91 burb:
removed the catalytic converter
removed all smog stuff (including the O2 sensor on newer trucks)
For a carb setup on a 350 or larger, get a low cfm (600-700) 4 barrel and run it a bit lean. The 4 barrel makes sure it has enough gas to power the truck with less need to really get on the gas. The best thing I did was get rid of that 2 barrel quadrajet which was giving me 10mpg city or highway, it had to struggle so much and pump more gas just to keep the truck going.
Dual exhaust with high flow mufflers helps a lot as well. helps to run 2" with a small block or 2.5" to 3" with big blocks.

This helped me get around 18-20 mpg highway and around 15 in town with my 76.
I still have the o2 sensor in my 91 (with 454 and TBI) but I typically see about 10mpg around town and the few highway trips I have taken I saw close to 15mpg. The burb also has a single 3.5" exhaust pipe so it is not restricting the flow as much as a smaller pipe would.

[chevyfan87]

removing an o2 is the dumbes thing you can do to a fual injected motor, as the stock setup relies on o2 readings to meter fual, and without it runs EXTREMELY RICH...meaning WORSE mileage not better

[Ivan D.]

Originally Posted by chevyfan87

removing an o2 is the dumbes thing you can do to a fual injected motor, as the stock setup relies on o2 readings to meter fual, and without it runs EXTREMELY RICH...meaning WORSE mileage not better

It ain't the dumbest thing, but tis up there indeed - the ECM usually looks at the O2 sensor only during the so-called "closed loop" conditions when cruising at a fairly steady speed with the engine all warmed up, so taking the 02 sensor out means the engine will never go into closed loop and will always run on the rich side - kinda like running on the freeway with your torque converter unlocked, you're wasting energy and not getting your best fuel economy. That said, you're still quite right, taking the O2 sensors off any computer-controlled vehicle is a just plain dumb, and nets you nothing but higher running costs and lower engine life expectancy.

[Ivan D.]

Originally Posted by screwballl

Dual exhaust with high flow mufflers helps a lot as well. helps to run 2" with a small block or 2.5" to 3" with big blocks.

On the exhaust thing - you really wanna step it down at least once along the length of the entire pipe, for a daily-driver small-block truck a good setup includes full length headers, 2.5" midpipes, 2.5" inlet 2" outlet high-flow mufflers, and behind them 2" tailpipes - main idea is that as the gases travel down the pipes they cool down and decrease their volume, and if you keep you pipes constant diameter that translate as loss of velocity near the rear end of the truck - stepping down the piping allows for high velocity even as the gases cool down, which makes for a better scavenging effect at the heads.

[rfmaster]

Originally Posted by Ivan D.

It ain't the dumbest thing, but tis up there indeed - the ECM usually looks at the O2 sensor only during the so-called "closed loop" conditions when cruising at a fairly steady speed with the engine all warmed up, so taking the 02 sensor out means the engine will never go into closed loop and will always run on the rich side - kinda like running on the freeway with your torque converter unlocked, you're wasting energy and not getting your best fuel economy. That said, you're still quite right, taking the O2 sensors off any computer-controlled vehicle is a just plain dumb, and nets you nothing but higher running costs and lower engine life expectancy.

Dumb??? nope- something else perhaps!
I have done my share of ECM data logging after completing Carb to EFI conversion. Based on my test drives GM ECM operates in closed loop about 95 percent of the time. Open loop operation occurs when O2 sensor is cold, at start up (ECM will enter close loop after CTS reaches 50C or after 2 minutes of engine run time, these values can be changed in EPROM if you have heated sensor). Open loop also takes place at WOT (and during brisk acceleration - Power Enrichment PE) and extended deceleration (DE and DFCO).

At WOT ECM commands injectors to deliver 12.3 to 12.9:1 mixture which corresponds to maximum power mixture for a gas engine. A conventional narrow band O2 sensor does not have range outside 14.7:1 to detect WOT mixture accurately (800 to 950 mV). Thus, ECM ignores O2 inputs during PE and WOT conditions.

During deceleration DE (coasting down) ECM will lean mixture up to 16:1 or more if certain conditions are met. During deceleration narrow band O2 reports very low values (80 to 120mV) which are not very accurate as well. If ECM detects extended deceleration it may cut of fuel all together - DFCO mode.

During highway driving some GM ECM will enter lean highway cruise mode if vehicle speed is above threshold and steady, and TPS is constant, as well as other parameters are met. ECM will lean out mixture and retard timing a bit to keep lean mixture from pinging since engine load is low.

Now - do you really want to hack that O2 sensor off??

//RF

[884x4Sub]

Originally Posted by rfmaster

Now - do you really want to hack that O2 sensor off??

//RF

I think what SB meant was he switched the sbc completely over to a carb set up and the bb still has the tbi with the 02 sensor......

awesome technical explanation though.......!!!!!!cool!!

[884x4Sub]

do the tbi spacers work........????

[884x4Sub]

Originally Posted by clean71

I don't normally like to put crap in my engine that says it does xyz. However, when I went to visit my parents in MT a few weeks ago, I met their neighbor, a very nice German lady who got the shaft by her husband and has been doing whatever she can to make ends meet. Anyway, long story short, she gave me a product to try that seems to work quite well. My DD is an '05 Nissan Titan that has gotten a high of 13-14 MPG since I've had it. The product she gave me is a fuel additive that is supposed to help the fuel burn more completely. I used it on my return trip from MT to AZ and recorded my mileage for the entire trip. Product was added 1/2oz at each fill up for three tanks and 1/4 after that. My average speed was 75-80MPH. Results were:

1st tank: 13.29MPG
2nd tank: 13.46MPG
3rd tank: 14.72MPG
4th tank: 17.4MPG
5th tank(some of this was around town driving when I got back): 16.5MPG

I made no changes in my driving habits and have continued to get above 16MPG for my daily 10 mile commute. Considering that I was averaging around 12MPG before, it's a nice litle change.

My dad has been getting between 35-40MPG in his Subaru Outback with this product.

This may or may not be for you but if interested, PM me. The company that she works for is an MLM. I have no financial interest in this whatsoever, but I'd rather give you her information via PM and ask that if you decide to buy the product, that you buy through her.

Long story short, her family owned a large department store chain in Germany. She inherited a couple million dollars, married an American guy who moved her to BFE in MT (I think everywhere in MT is BFE isn't it?) and subsequently squandered her money and left. My parents help her as much as they can and she works her but off to pay her bills and eat. So, anything you can do to help would be great.

If anyone has a problem with this post, I'll delete. Just think it seems to be a decent product and it would help my parent's friend out. If you PM, I'll give you her number and you can call her, talk to her, and make your own determination.

so......whats the product????

[rfmaster]

Originally Posted by 884x4Sub

do the tbi spacers work........????

I can not quantify effect of TB spacer in my setup. I run 1 inch spacer in my setup since I need (must have) fuel line clearance between TB and intake manifold. Thus, I can not perform with and without comparisons. Increasing manifold volume and consequently increasing inlet air-fuel mixture speed between throttle plates and main manifold volume appears to have subtle benefits - better throttle response and fuel mixture balance.
Carburetor is a wonderful fuel mixing device, but when it comes to precession fuel mixture control over wide operating conditions it is not it. Conventional (non computer controlled) carbs always operate in open loop.

//RF

[D-Day]

I forgot to mention the manifold on my truck is an Edelbrock Performer, with a Mallory distributor, and NGK Iridium plugs.

[jimfulco]

I don't know how your carb & distributor are set up, but I'll tell you what I can about my '69 SWB. As far as I know, it's the stock 350 4-bbl with 3-on-the-tree and single exhaust, at least at the time I bought it in 1979. It had 33x12x15 Gumbo Mudders on the back, and bias-belted car tires on the front. I'm assuming 3.07 gears because it would go 40mph in low gear.

I installed a cheap advance curve kit in the distributor, using the lightest springs in the kit, and set the total mechanical advance to 36*BTDC. Vacuum advance was hooked to manifold vacuum, but I have no idea how much advance it added. The air cleaner lid was flipped, leaving a ~1/2" gap all the way around.

The truck got a calculated 15mpg around town and 17 on the highway, but that was with the stock speedometer gearing, so it was actually more than that. It did tend to ping a bit under load with regular gas, so I changed the distributor springs to the medium ones, but I never checked the mileage after that.