Grumpy Bears 2015 Silverado 2WD

KARNUT · July 17, 2017

A few times I've re geared for performance and got better gas mileage. Most times in the 70s-80s. My dominant cars where impalas. They were great for 273s with 350s. Mostly used by the wife in town and gain 2-4 mpg with 373s. Being it was the double nickel days didn't suffer on the interstate. I'm with go with gears camp.

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Edited July 17, 2017 by KARNUT

Grumpy Bear · July 18, 2017

A few times I've re geared for performance and got better gas mileage. Most times in the 70s-80s. My dominant cars where impalas. They were great for 273s with 350s. Mostly used by the wife in town and gain 2-4 mpg with 373s. Being it was the double nickel days didn't suffer on the interstate. I'm with go with gears camp.

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I've run 4.30's back in the day when I was both younger and dumber. The 66 Ford wasn't sporting a double over drive though. It also didn't have a 4.03 first gear in it either. You could run a 4.56 in these on factory tire sizes and still run 75 mph all day. Not that I would. The Ford was spinning 3K at 60 mph. Busy big blocks.

I looked briefly at the 3.48's and 3.73's. Spent some considerable time looking at the 3.90, 4.10, 4.3 and 4.56 sets. Last night I tossed the 4.56 gears. First gear would just be to low. Who thought a 4.03 first was a good idea? 2.80/2.90 would have been more than enough. Anyway, of the remaining three the 3.90 is looking iffy for what I want to do with it.

Grumpy Bear · July 20, 2017

35,000 miles went by quickly enough. Let’s start with the tires. Bought a new depth gauge. Analog direct reading dial type that measures in quarters of 1/32 inch or 1/128^th of an inch. As such the reads are quick and easy to read making multiple reads per tire per tread averaged easy peasy in the noggin. We have .2265 of the original .3125 left. A self-imposed 1/8^th inch minimum bound by the lower readings from the outside groves gives 41K left or 76K estimated tread life. Too bad I didn’t discover the toe issue until it was too late. Note to self. Adjust toe to .04+ from .04- to counter mild negative camber. Safety checks, check. Fluids, check. Projected numbers are declining as I’ve elected to run lower air pressures for comfort sake. 32 psig cold.

Mobil 1 testing finished I moved on to the Red Line 5W20 fill and then went driving taking notes as I went to add to the graph. After hours of driving and nearly 300 miles I felt good about what I was seeing, feeling and hearing. Did I mention today was a blister? 93 degrees F, humid and dead still air or nearly so. Giving 20 miles per 5 mph increments I logged air, water, trans and oil temperatures along with the incremental mpg numbers along with some notes and observations. Did this twice. Once in Drive and once in M5 after a cool down. The 50, 55 and 60 mph numbers actually in Tow Mode 5^th gear to keep the AFM active. It will stay in 5^th between those speeds. Then….I opened the window to let out a fly the pup was after before we end in a ditch…and…out the window my notes go…Grrrrrrrrrrrrrrrrrrrr.

I’m out of time. Out of patients and just out of it in general. So in generalities until I can recreate the file:

First and foremost. Here’s the 411 on the OLM. It’s 75 miles per 1% no matter what. Three oils, two thermostats and 45 degrees of range. Run it in 4^th if you like. It’s still 75 miles per 1 percent.

Run what ya like for oil but I’m keeping the Redline. I’m keeping the 5W20 not matter what GM says; no matter what the bloggers say. K thermocouples don’t lie and neither do calculated mpg numbers over long distances. Especially in back to back to back test. I could care less about GM’s warranty. I’m keeping the 180 F thermostat. I can run 70 mph as cool than as stock at 40 mph and at significantly higher fuel efficiency.

After today I have to really rethink the re-gearing. I was stunned over the results. Enough so this goes on the back burner until I find the break point. Which is telling you that below a certain speed the lower gear is a significant help and above a noticeable hindrance. At least without a cooler. Not unsafely so but enough so to make you give your oil choice a good hard look. The question is...what speed do I see me running on average for the next 20 years.

Edited July 20, 2017 by Grumpy Bear

Grumpy Bear · July 21, 2017

The change to Red Line Lubricant has been a game changer. Cliché I know but…I so was not expecting what changes. Yea, I expected it to run cooler. I expected it to be a bit freer. I did not expect the effect it would have on the AFM and frankly, I should have. Also didn’t see the effect it would have on water temperature.

On air cooled motors oil temperature reduction is direct reading and astounding. Just the Mineral oil to Ester change lowered the oil temperature 15 F in my 2005 HD FLHC. You don’t get that directly with a water cooled motor as oil isnt’ the leader in the cooling deparment. So unlike the change from Quaker State to Mobil one that showed a step change. The change from Mobil 1 to Red Line did give a few degrees relief at both ends of the speed range but was the same +/- 1 degree in the middle. Where the improved lubricity and increased thremal capacity showed up was at the water temperature gauge of all places. Under 50 mph the thermostat wont thottle. Wont stay open. The engine heat load is so low that with out a thermastat I have no idea how cold it would run. Oil temperatures will however remain below 208 F even at 60 mph on a 95 F day. That’s huge.

Increased thermal capacity not only makes it run cooler. It makes it heat up qicker too. About 15-20% quicker. Qucker heat ups help short trip mileage.

To the heart of it then. The AFM is load triggered and what happenes when you reduce the load? It stays on a larger percentage of the time. I’d say magic but it isn’t. It’s good ol fashion physics. In two days I already have a thousand miles on this oil change and the 30 mpg I hit once in the previous 25,000 recorded miles on a perfect day at 45-50 mph highway is now turn key easy at 50 . In fact at 45 mph 33 mpg isn’t hard. Over 30 mpg in tow mode and 5^th gear at this speed.

Something else unexpected. The better mileage I had been getting in 5^th gear AFM active is no longer the case. The advantage has shifted entirely to the 3.23 gear set with one oddity. 4.5% better in fact for the entire speed range avearged. 7% better at 45 mph 2.7% at 50 mph and 4.1-4.5% at 55 mph and above. That little dip in the curve is the oddity.

In a head wind it will get better mileage with the 4.1 gear than the 3.23. But with the wind at your back the advantage is significantly bias to the 3.23 meaning tow 5 might have an impact on fuel economy as a situational stratigey in stong head winds. I broke even on this day of 5 mph winds. More test will be needed to quanify and satisty myself.

So don’t need a cooler now and the gear change for sake of the ratio is off the table. Still need a new set though for the Torsen Diffrenetial install. So will stay closer to factory.

Edited July 21, 2017 by Grumpy Bear

Grumpy Bear · July 22, 2017

Here’s the oil type temperature results graphed. Looks better than the raw table data looked. I’m happy. Wish I had thought to gather data in the beginning with the GM 5W30 oil and the 207 F thermostat. It would have been scary and I’m not about to digress now.

So…here’s your disclaimer. Kids, don’t try this at home.

Don’t use this study or this data to cry over or blame me for a burnt up motor if you decide to run 20 weight group 2 lubricants while towing the max on the speed limiter on a hundred degree plus day crossing Death Valley. I know someone will try cause it‘s what we do.

Why does this work? Heat management. Think I’ve said it before. Motor doesn’t care what the API says or what the viscosity is in the bottle on the self on in some test apparatus. It lives in the moment and in the real world.

Grumpy Bear · July 25, 2017

Install Scan Gauge. Helped me identify the AFM triggers. Quantify the mpg/mph curve. Learn how weather effected the systems. See things in the system that are otherwise hidden. Linear Logic sent a data logger to help find all hidden PID addresses on ECU to maximize data acquisition.

Used Scan Gauge to identify poor driving habits and refine. HUGE dividends for some rather minor tweaks. Real time graphing would help more and an option to be gathered up soon.

Have an alignment performed. Not just to get in “within spec’ but to perfect the spec for lowest drag. Still tweaking this one. Scan Gauge helped find the best settings along with tire wear tracking. Also improved ride quality immensely. Major step change.

Install Jet 180 F thermostat and Red Line water wetter to lower coolant temperature. Scan Gauge readings of water, trans and oil temperatures showed the factory DIC water gauge was highly inaccurate and insensitive. Pointed out the ridiculously high temperatures they are asked run at AND the effect that has on oil temperature vs speed and load. Confirmed lower operating temperatures allows use of 5 or even 0W20 lubricants.

Sorted oils to find the slickest coolest running oil that kept the AFM active the highest percentage of the time. Red Line by the case. Results in about the same step increase in mileage as sorting the alignment. A biggie. Quicker heat ups and quicker cool downs. Next case will be 0W20.

Suspension changes are in the works. Ordered and paid for. This is mainly a comfort thing but I did not waste the opportunity to lower the truck to level via the new rear leaf package.

I have some moves left in tire selection and pressure refinements and gearing and lubrication changes in the trans and differential as time and resources permit. Some refinement in coolant concentrations and aux oil/water cooling/preheat. If that all pans out, and I expect it will then on to a trans tune and further ECU AFM enhancements. Some minor aero tweaks I put on the back burner that were promising.

55 mph is now giving better mileage returns even in moderate winds on undulated ground than stock did at 45 mph. 60 mph Interstate speeds are often possible now and stay over 27 mpg.

Graph is running life time fuel consumption by tank cumulative. (blue) Orange is the last combine 24 tank rolling average. As long as orange stays above blue, blue continues to rise an as you can see the amount it is above is significant.

FYI: The last six tanks combine have produced 27.5 mpg over 2750 miles. I was asked if I thought that was possible…there’s the answer.

Grumpy Bear · July 26, 2017

I hate to embarrass myself. It’s why I’ve been sketchy with the suspension project. I was unsure of my ability to close the deal. It’s a lot of $$$$. However springs are ordered and financing assured and it seems I have a clear path to completion. What I don’t have is a huge amount of construction detail to share as it hasn’t been fully shared with me. But in broad strokes:

I went to Ben Brazda at Filthy Motorsports for a conference outlining my project goals to see if this was something he could help me with and as it happened, he could. He could because while not what they do it is a project he just completed for himself. How fortuitous. We wanted the same thing. Remove the harshness and provide the control the factory left out on his truck.

Ben explained the issues involved and number of ways they could be addressed and then I complicated things…I asked for a suspension drop instead of a lift. Not in their wheelhouse. Further the methods used to enhance a firm controlled ride are counter to a drop.

My truck is equipped with springs that are rated to carry 2200 lbs. each. That doesn’t translate directly to a spring rate. Rate is the number of pounds required to deflect the spring one inch. The coils up front for example say have a 300lb/inch rate and say 4 inches of travel to just before coil bind. So the springs load capacity is then 1200 lbs. Doesn’t work that way with leaves. Leaves are progressive by nature. Takes more load to compress the second inch than the first and more for the third than the second. How much depends on the number of leaves in the package and the thickness and length of each leaf. GM on the cheap says do it in as few leaves as possible which means thick leaves with large initial rates and huge length steps.

You can build a spring either way and still get 2200 load capacity over say 4 inches but one has a softer initial rate with a more progressive nature than the other. It means allot of thin leaves with progressively shorter lengths. It also means the spring package is allot thicker and there lies the rub to a drop. Ride height is affected by the thicker package and in the wrong direction for a drop. The possible remedies are, remove the 1-1/4” spacer and/or flatten the leaf arch. I’m asking for a 2” drop. The arch has to be allot flatter and there is the snag.

A leaf spring has a minimum arch height for a given leaf perch distance. Is this possible? That needed to go to engineering at Deaver Springs in California and they came up with a killer plan that they say is a go. Scott the project guy there says the engineers say; Yes remove the block. Yes flatten the arc but to keep it workable, the spring eye are going to be flipped.

So why not just use a lowering shackle? Because the truck is receiving Sulastic isolation hangers that are one eye to eye length only. Their value in helping accomplish the project goals is too large to ignore in Ben’s opinion. There is also a minimum distance requirement between the axle and frame to be considered.

This is getting long so I’ll leave the rest for a second post. I've exceeded my 500 word limit.

Edited July 26, 2017 by Grumpy Bear

Grumpy Bear · July 27, 2017

So we have a thicker spring package with more leaves that are thinner and smaller length steps. We have reversed eyes. Flatter arches. Blocks removed and Sulastic hangers. We have our drop, enough load capacity and enough axle frame clearance and we have a very progressive spring.

All this monkey motion was to give a spring rebound force that was within a hydraulic shock absorbers capability to control…effectively…and prevent the suspension from ratcheting down to the bumpers on a washboard. It also enhanced compression rate progression without giving up capacity. If I would have allowed stock ride height, load and tow capacity would have remained unaffected. I don’t tow so I didn’t care. And if I ever do it can be bagged.

Violent rebound is what makes the trucks ride harsh and uncontrolled. They just cannot dial in enough rebound dampening in any shock, stock or otherwise for the way these stock springs are engineered. It’s why your Bilstein, Bell or Fox modify but cannot correct nor reflect a good dollar value for what they bring to the table. Nothing off the self is going to match the new spring package thus some custom valving is in order but I digress…

Up front we have the same issues for different reasons with similar but different solutions. Stock ride height means I get to keep stock geometry and a level truck with what’s going on out back. But it too needs a change of spring from linear to very progressive and that requires new dampening rates as well. This is where Ben earns his money. He’s picking the front spring to balance the new rears and custom valving the King shocks and struts that will be dampening this combination. $$$$ ticket items.

Yes I know this is taking a nine pound hammer to drive a thumb tac but what other choice do I have? None…none worth their money. None I care to make. In essence I’m not paying for the King Shocks quality or its tunability or its infinite rebuildability. I’m paying for Bens ability and expertise in sorting this thing out finitely. Okay, I am…but

Boys, I will have my cake and eat it too. It’s just going to cost me.

Grumpy Bear · July 31, 2017

17.0 mpg = Federal Data base recorded for this truck.

24.0 mpg = EPA sticker high way estimates.

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24.6 mpg = Factory Fill Delco 5W30 as delivered to me.

26.0 mpg = Alignment

25.9 mpg = Quaker State UD 5W20

27.9 mpg = Quaker State Plus 180 F Thermostat

26.0 mpg = M5 AFM locked out

27.4 mpg = Mobil 1

28.8 mpg = Red Line 5W20 Plus 180 Thermostat

The alignment was good for +5.7% increase

The Switch to 5W20 Quaker State UD was a net loss as a stand-alone but when coupled with a cooler thermostat netted a 7.31% gain. I’ll come back to this.

Running in M5 with the AFM off put it back to the alignment number erasing the gains of thinner fluids and cooler temperatures.

Mobil 1 was a 1.8% looser but still gave a cooler running temperature. Not sure what to make of that.

Red Line 5W20 was a 3.2% gain over the previous best QSUD numbers.

Net gain, 17.7% over delivery numbers and an even 20% over the EPA sticker number.

I may have said this before. If a lighter oil gives a cooler temperature as a stand-alone heat was viscosity friction related. If it gets hotter there is an increase in surface to surface contact. Not good. If a heavier oil provides a cooler temperature it is eliminating surface to surface contact. If the heavier oil gives a hotter temperature viscosity fiction is the primary. This is a preface to the ‘I’ll come back to this’ comment. Obviously the thinner fluid alone was not thick enough at operating temperatures to prevent metal to metal contact. Cooling the motor increased the viscosity enough no only to cool it back down but further than the thicker oil did uncooled telling me it was still thinner and more lubricous. In other words, fell in between the two. I get to benefit from the Polyol’s best features without sacrificing efficiency.

A word about break in. It still isn’t done with this process and there has been some benefit from the break in adding to the efficiency all along. The numbers are ‘relative’ to each other and not absolutes. That said it is indeed well along. That little puff of morning blue smoke is no longer with us and has been absent for weeks.

Not everything I try works but you see it fail here.

So our winners are, and still rising……. (see red bold above).

Edited July 31, 2017 by Grumpy Bear

Grumpy Bear · August 2, 2017

Talked to Ben Brazda at length today on the telephone and we concluded our business. Three to four weeks. (Filthy Motorsports)

And we have a snag. Communication breakdowns in a three way project are bound to happen. I missed that the King OEM replacements are an automatic 2” leveling lift MINIMUM to compensate for a GM geometry error that leaves the front struts way off stroke center that requires a shim pack so stiff that it would undo everything I’m trying to accomplish. The work arounds all have issues I am unwilling to deal with.

This is a huge issue as the rear is 2” lower. The leaf springs are in production and too late to change the direction of that boat. It left the harbor last week.

After a hour looking at all possible solutions there was one that keeps the intent and execution of the project on task. 2” dropped spindles which only resorts stock ride height but keeps the geometry perfect and the valving on target. The spring selection balanced and the truck near neutral steering. Every project has cost overruns.

I still get to keep my rear level and my wife almost happy. Eventually when parts start to show up I’ll have pictures.

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On another note. Packed on the miles today killing another tank of fuel on an absolutely perfect Illinois day. Those are rare as hens teeth and we’ve had five in a row. Partly sunny, 80 F, 40% humidity and 0-3 mph winds all day except for two quick rain showers with short burst of 15 mph gust. Nothing really.

The day started with 75 miles already on the tank and the indicator showing 29.5 mpg. Three trips to town but not IN town. Ended with 438 miles using 13.753 gallon of fuel for 31.85 mpg and there is more to go. To reach that number the remaining 363 miles were run at 32.54 mpg to get this result. That makes four tanks averaging 29.5 mpg and two over 30 mpg running 55 mph.

Since the Red Line fill this thing has been crazy smooth and holding on to the AFM allot. Pulling 3% hills over 30 mpg into 5 mph winds sort of crazy.

I am pretty sure that all the low hanging fruit is now picked and we wait for averages to peak. That may take a few years at this pace. Or a good winter weather set back.

Edited August 2, 2017 by Grumpy Bear