Improving fuel economy

[2000StreetRod]

Advancing the camshafts?

According to an article posted on AA1CAR.com advancing the camshafts a few degrees improves throttle response and low speed torque with minimal degradation of max rpm performance. Jakee mentioned in a post that some of the Mustang SOHC V6 owners advance their camshafts about 5 degrees. Advancing the camshafts would also help compensate for the timing chains stretching and the chain guides wearing down.

Does anyone have an opinion or tried it and have measured results? I don't recall Al Franklin ever discussing it. I'm going to do more internet searching and may try advancing the camshaft timing five crankshaft degrees (i.e. set the crankshaft at 5 degrees before TDC and then align the camshaft timing slots).

Stock camshaft timing:
185 degrees intake duration @ .050,
193 degrees exhaust duration @ .050,
0.472” valve lift with 116 degree lobe separation.

 

[2000StreetRod]

knock sensor retard

I've known ever since my custom tune that I have a problem with the PCM retarding the spark advance at WOT due to the knock sensor. I have recorded as much as 8 degrees of knock sensor retard at WOT even with premium fuel in the tank. I assumed at the time it was due to the sensor responding to my timing chain rattle but replacing the timing chain components made no change in the knock sensor retard.

Retarding the ignition timing from optimum advance significantly decreases maximum performance. I reviewed a datalog from my 3 to 4 upshift flare problem and found that even at moderate throttle up to two degrees of knock sensor retard was occurring. I suspect that the nonoptimum ignition advance may adversely impact fuel economy. I'm considering purchasing an AIRTEX / WELLS Part # 5S2221 available from Rock Auto because it has the plastic plug to keep the connector in place.

The Standard brand part does not have the plastic plug on the connector so it can flop around.

I couldn't find one listed on Tasca or Tousley parts.

Does anyone have a knock sensor recommendation?

 

[2000StreetRod]

underdrive pulley?

Al Franklin thought his most beneficial modification to increase highway fuel economy was an underdrive pulley. A smaller diameter than stock crankshaft pulley slows the belt speed reducing the RPM and drag of the alternator, water pump with cooling fan, power steering pump and A/C compressor. Al eventually switched to an electric cooling fan and a 200 amp alternator with an overdrive pulley. I question whether an electric cooling fan is justified for highway driving since the unaided airflow thru the radiator at highway speeds should be adequate. I found a new ASP 2005 to 2009 Mustang V6 crankshaft underdrive pulley on the internet for $273 with free shipping. I have not been able to find an overdrive pulley for the alternator. I would also have to purchase a shorter serpentine belt. I suspect the reduced drag associated with a slower speed water pump and cooling fan are the main contributors to increased fuel economy. The A/C compressor will just stay engaged longer to compensate for turning at a slower speed and probably not save any fuel. For my situation of almost all city driving I doubt that switching to an underdrive pulley is appropriate.

 

[Karpiel73]

I tried non-ethanol gasoline with this last tank of gas. The AC compressor was unplugged and the roof rack was removed (the ex gains 3.5 mpg highway just by removing the rack) for the trip to Savannah. About 90 miles was city driving. The highway driving did not go above 67 mph (cruise control). So here's the results for this:

351.7 miles on the tank (most i've ever got)
16.309 gallons to fill it up (still had ALOT left in it)
21.57 mpg's (best mpg's to date! 20.8 was best prior to this)

I had a gain in the mid-range power without a doubt. But I contribute no large gain in mpg's because of the 90 miles in the city.

So would I do use non-ethy again? Yes-minus the city driving of course!
The extra .50/gal did hurt though!

 

[2000StreetRod]

fuel economics

I tried non-ethanol gasoline with this last tank of gas. . . 351.7 miles on the tank (most i've ever got)
16.309 gallons to fill it up (still had ALOT left in it)
21.57 mpg's (best mpg's to date! 20.8 was best prior to this) . .
So would I do use non-ethy again? Yes-minus the city driving of course!
The extra .50/gal did hurt though!

Assuming 10% ethanol costs $3.50/gal and non-ethanol $4.00/gal:

4.00/3.50 = 1.143 or an increase of 14.3%

Assuming 10% ethanol provides 20 mpg highway

To break even with non-ethanol:
20 * 1.143 = 22.86 mpg

 

[Karpiel73]

Assuming 10% ethanol costs $3.50/gal and non-ethanol $4.00/gal:

4.00/3.50 = 1.143 or an increase of 14.3%

Assuming 10% ethanol provides 20 mpg highway

To break even with non-ethanol:
20 * 1.143 = 22.86 mpg

Impressive. I was wondering how I was going to figure that out but you did it for me. Thanks! I was still a long shot from breaking even then. Have you considered non-ethanol for long trips? I see you get better gas mileage than mine already.

 

[2000StreetRod]

Fuel injector cleaner

My fuel economy improved slightly on the last tank.
214.6 miles/12.928 gals = 16.6 mpg

The changes from the previous tank full (16.5 mpg):
20 ounce bottle of Techron fuel injector cleaner

It's been less than a year since I added a bottle of fuel injector cleaner so I wasn't expecting much improvement (if any). I can't do anything signficant for the next tank. My Volvo is in the garage and immobile and the subdivision covenants prohibit working on vehicles in the driveway. The only change will be increasing the tire pressures. My objective is to make one possible improvement at the beginning of each refill.

 

[FIND]

Wow... Here non-ethanol gas only costs 10 cents extra...

 

[2000StreetRod]

Electric water pump?

Has anyone switched to an electric water pump? I checked a couple of the Mustang forums and several of their members use them on their daily driver supercharged/turbocharged V8s. Meziere makes a 20 GPM remote water pump with a two year unlimited mileage guarantee and an estimated service life of 3,000+ hours. The cost of the pump with fittings, hoses, relay control, etc. would be around $300. I only drive my Sport about 3,000 miles per year and its almost all city driving. If I average 20 mph, 3,000 miles represents 150 hours. At that rate the pump would last 20 years. The pump draws between 6 and 7 amps. The instructions indicate it is "designed to be spliced into the lower radiator hose of almost any vehicle. This eliminates the need to drive the stock water pump." That seems odd to me. I'll have to investigate what the flow thru the block would be if the thermostat is closed. Serpentine belt routing and the need for a radiator electric cooling fan are also issues.

 

[2000StreetRod]

remote water pump rejected

Last night I had a chance to purchase a Meziere WP136S remote electric water pump via eBay for $150.

It only had 1 hour usage and included the hose adapters that cost $18 each so it was a bargain. I rejected the purchase temptation for several reasons. It only had 20 GPM flow. It must be mounted vertically, preferably near the lower radiator outlet, and I couldn't find space since its 7.25 inches tall with a 3 x 3 inch body. I would want to eliminate the stock water pump and mount an electric motor in its place to drive a radiator fan but can't eliminate the water pump pulley because of the serpentine belt routing.

The water pump pulley allows the serpentine belt to wrap the crankshaft pulley for 180 degrees preventing belt slip. The electric water pumps for popular engines mount in the same location as the stock pump and include an idler pulley to maintain the serpentine belt configuration. I could not think of an alternative solution.

The main advantage of an electric water pump is good flow at low engine speeds and reduced drag at high engine speeds. I doubt there would be much improvement in fuel economy by switching to an electric pump but there would be an improvement in WOT performance. However, the ideal location for mounting a radiator electric fan motor is where the stock water pump is. The ideal solution would be an electric motor bolt on replacment pump with an idler pulley and an electric fan clutch. The water pump would rotate at a constant speed and the fan engagement would be thermostatically controlled.

 

[2000StreetRod]

Electro-hydraulic power steering pump?

While performing my knock sensor replacement I noticed there is some engine compartment space going to waste under the battery tray. Driving my Volvo 850 turbowagon has increased my interest in forced induction. One possible location for a centrifugal supercharger is where the power steering pump is presently located. Al Franklin (aldive) noted fuel economy improvement when switching to an underdrive crankshaft pulley. He eventually added an alternator overdrive pulley and a 200 amp alternator to improve current output at engine idle. That means that his fuel economy gain was due to reduced water pump/cooling fan drag and power steering pump drag. It would be desirable to gain better fuel economy and space for a possible supercharger by converting to an electro-hydraulic power steering pump located under the battery tray.

I had a chance to purchase an integrated power steering pump assembly on a local wrecked 2004 Mazda 3 for $100. They go for around $300 on eBay. I learned that the unit requires a steering angle sensor (SAS) that is mounted on the steering column. The SAS output determines how fast the pump rotates and therefore the amount of steering assist. The steering pump is a smart unit that interfaces to the PCM via the later update to the OBDII bus. I decided that the unit would be too difficult to integrate into my Sport. I also briefly looked at the steering pump on the later MiniCoopers but it appears to have a similar implementation. I've started looking for older technology with an easier pump to integrate but not as good fuel savings.

 

[masospaghetti]

This is a great thread, thanks for documenting all of this.

I've also contemplated replacing the heavy stock steel spare with an aluminum one although not sure how much savings is to be had here. Never considered a smaller battery though.

Are you sure such low ATF temperatures are a good thing? I always thought that the ATF should be at engine operating temperature, and anything significantly below that would degrade transmission life and efficiency.

 

[2000StreetRod]

Oil Optimum temperature

According to available documentation there is an internal thermostat in the 5R55E that controls the external cooling loop. The thermostat opens when the torque converter temperature increases to 150 degrees F. I assume the transmission manufacturer has determined 150 degrees to be the optimum temperature. The external coolers allow the ATF to cool when the external loop is open. The greater the external cooling loop capacity the sooner the internal temperature can be returned to optimum after exceeding it.

There seems to be a debate about optimum engine oil temperature. Some say 180 degrees F is best. Others say about 215 degrees because that is above the boiling point of the water vapor in the oil. The engine oil temperature should always be kept below 240 degrees. I've decided to go with 215 degrees to get best performance and fuel economy.

 

[masospaghetti]

Gotcha. I did not realize the 5R55E had an internal thermostat.

As far as oil temperature, I've always believed that higher temps (to a point, of course) improve the combustion efficiency because less heat is lost into the coolant, therefore this will result in higher fuel economy. However, a lower temp such as 180 F is better for maximum power, because the lower temperatures prevent preignition.

 

[2000StreetRod]

Oil's primary function

. . . As far as oil temperature, I've always believed that higher temps (to a point, of course) improve the combustion efficiency because less heat is lost into the coolant, therefore this will result in higher fuel economy. However, a lower temp such as 180 F is better for maximum power, because the lower temperatures prevent preignition.

The primary function of oil is lubrication (i.e. preventing metal to metal surface contact). I agree that oil also provides limited cooling but cooling is the primary function of the engine coolant. It takes more power to pump cold oil than warm oil. One advantage of synthetic oils is they flow well at cold temperatures. This is especially important in areas with very cold winters. I can remember years ago Corvettes switched to synthetics in their new vehicles because engine bearings were being destroyed in cold weather starts with conventional oil. Canton Racing has determined that 215 degrees is an optimum temperature for their oil cooler thermostat and that is what I'm going with. See post #63 of Oil Coolers Since I switched from a single row to two row radiator I have no engine cooling problems. See Hood lifts, side steps & radiator

 

[joecrna]

Dale, can't believe I missed your thread. Though we use our Explorers in completly different ways, they seem to have several similarities. For instance, I too use a two row aluminum radiator that many may consider overkill (no problem cooling even 4 wheeling in Death Valley at 118 F). The ATF is likewise treated to significant cooling. Trans output (temp regulator functioning), to coolant radiator, to filter, to 180 full open thermostat, to 29,500 BTU remote cooler, to factory remote cooler and back to the trans pan.

I've seen many ATF temps mentioned in various threads but people often forget how much it matters where in the fluid path the temp is taken. I monitor mine at multiple locations, the output line from the trans (160-185 F), the input line going to the pan (usually ambient to 50 F above) and between coolers (output temp to 20 degrees less regardless of output temp). It would seem that the coolant radiator adds no significant heat to the ATF. I don't know why. It should.

I don't know how this might help your project. I just thought I would give you some additional data. By the way, my '98 has what seems to a slight hybrid intake. Not variable and with a returnless fuel system but the fuel lines enter from the back.

 

[2000StreetRod]

radiator temperature

. . . It would seem that the coolant radiator adds no significant heat to the ATF. I don't know why. It should.

I don't know how this might help your project. I just thought I would give you some additional data. By the way, my '98 has what seems to a slight hybrid intake. Not variable and with a returnless fuel system but the fuel lines enter from the back.

Thanks for the information Joe. I have an infrared remote reading thermostat and have learned that my radiator external temperature is usually less than 150 degrees F. Because of the temperature the coolant 195 degree F thermostat opens for brief periods but frequently. I monitor the transmission ATF output temperature at the input of my remote full flow filter. I also watch it periodically with an SCT Power Flash datalog.

Your vehicle may have been a late 1998 made during the transition to 1999 model. I have purchased a VIS manifold and will convert to it after my oil cooler rework and possibly dyno testing.

 

[masospaghetti]

The primary function of oil is lubrication (i.e. preventing metal to metal surface contact). I agree that oil also provides limited cooling but cooling is the primary function of the engine coolant. It takes more power to pump cold oil than warm oil.

Definitely, I was inferring though that higher oil temperatures also mean higher coolant temperatures, which means the engine is retaining more heat - thus less heat transfer through the radiator.

 

[2000StreetRod]

Tire pressure

My fuel economy decreased slightly on the last tank.
231.4 miles/14.413 gals = 16.05 mpg
214.6 miles/12.928 gals = 16.6 mpg
Average for last two tanks
446 miles/27.341 gals = 16.3 mpg

The changes from the previous tank full (16.6 mpg):
Increased tire pressures from about 22 psi to 35 psi. The vehicle seems to roll better going downhill and corners better but there was no improvement in fuel economy. The weather here has been unseasonably warm so I used the air conditioning some. Also, I was not able to use my "standard" gas pump. I probably won't count this tankfull because I hope to datalog some WOT tests to see if the new knock sensor is working properly.

 

[2000StreetRod]

boulevard driving

My fuel economy increased significantly on the last tank.
224.1 miles/12.663 gals = 17.70 mpg
previous tank:
231.4 miles/14.413 gals = 16.05 mpg
Average for last two tanks
455.5 miles/27.076 gals = 16.82 mpg

There were no vehicle changes from the previous tank full but much of my driving was on boulevards with fewer traffic signals. I did not run the air conditioning in spite of the warm weather. Once again I was not able to use my "standard" gas pump. I wish all gas pumps would have level parking spots. I did not have an opportunity to perform any WOT datalogging. Hopefully I'll have time on the current tank. I suspect as the weather gets hotter my fuel economy will suffer since my intake currently pulls air from the engine compartment.