Grumpy Bears 2015 Silverado 2WD

Grumpy Bear · March 13, 2017

Today I found nine more records preceeding the current string with one overlapping the current record to date adding eight to the string for improved accuracy.

Each fills median value is 18.67 gallons. I have the SG set for 19 to empty, it showing 18.94 median gallons per fill. A bit over a quarter gallon error favoring the pump. Median distance driven per tank 476 miles. 11,488 mile of record using 451.9 meaured gallons = 25.42 mpg. +/- .961

Fill variation of about a quarter gallon accounts for about .35 mpg plus minus the average. More than half the signal noise.

Referece post #42: 29.33; +/- .84 mpg for six cycles at 50 mph of hypermiling. We (I) know have an answer to a few questions.

Driving technique and use of the Scan Gauge saves 15% in fuel. Half the advertised and still worth its cost.

My “normal’ driving style still nets better than the EPA ‘sticker’ average which according to common complains is a major coup.

New points on the graph are to the left.

Grumpy Bear · March 14, 2017

WOW! If they are light enough, me and da wife is have'n a conversation. Those ROCK.

Can you say ROCK at my age?

Click on the photo and blow it up. Thoughts welcome.

Edited March 14, 2017 by Grumpy Bear

Grumpy Bear · March 17, 2017

Well KMC dropped me a line saying they would get me an answer and yet they have not. As the point of the exercise is lower wheel weight and wheel rate…

Wife isn’t impressed either. I think it’s more the cost than the look. I really do like them though.

That said it doesn’t hurt to keep looking and continued search found these.

Even American Racing is made in China now so it hardly matters these Ultras are. I certainly can’t afford Foose. These are half the money.

Oh, they are close to factory spec measurement. That is 17 x 8 with a +25 mm offset.

Late correction; Ultra and the outlet, Tire Rack do not seem to agree on wheel weights. So the photo I had posted earlier (Mako) picked from Tire Rack that showed a 25 lbs. wheel is actually 31 according to Ultra. This wheel (Rogue) is show on Tire Rack as 25 lbs. but is actually 26. Devil is in the details.

Click on truck photo for larger view.

Edited March 17, 2017 by Grumpy Bear

Madcow2020 · March 17, 2017

Well KMC dropped me a line saying they would get me an answer and yet they have not. As the point of the exercise is lower wheel weight and wheel rate…

Wife isn’t impressed either. I think it’s more the cost than the look. I really do like them though.

That said it doesn’t hurt to keep looking and continued search found these.

Even American Racing is made in China now so it hardly matters these Ultras are. I certainly can’t afford Foose. These are half the money.

Oh, they are close to factory spec measurement. That is 17 x 8 with a +25 mm offset.

Late correction; Ultra and the outlet, Tire Rack do not seem to agree on wheel weights. So the photo I had posted earlier (Mako) picked from Tire Rack that showed a 25 lbs. wheel is actually 31 according to Ultra. This wheel (Rogue) is show on Tire Rack as 25 lbs. but is actually 26. Devil is in the details.

Click on truck photo for larger view.

I think these look really nice.

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Grumpy Bear · March 17, 2017

I think these look really nice.

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This second set?

Madcow2020 · March 17, 2017

Yes the second set.

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Grumpy Bear · March 17, 2017

Another thought not based soley on weight although a few pounds lighter. A brand I actually have some experience with. They were OEM on my first Honda.

Madcow2020 · March 19, 2017

They would look good on the truck, but I personally liked the second ones more. I am just a guy in the web behind a keyboard. Lol. The third one probably is a little more timeless design.

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HoosierZ · March 19, 2017

I like those Enkei wheels. I'm not crazy about the lettering on the rim of the Ultras. Look at the Enkei M6 wheels. They use their MAT process to make them strong and light weight.

diyer2 · March 19, 2017

Another thought not based soley on weight although a few pounds lighter. A brand I actually have some experience with. They were OEM on my first Honda.

Grumpy Bear · March 19, 2017

Enkei ST6 17 X 8 +35 Pretty close to an OEM replacement. 28 lbs. they say.

Here’s the rub I’m having. Those that have them don’t have them in the offset I want although it is a stock item. Those that don’t have them can get them with some ridiculously long lead time. A few that have them want $50 a wheel or more than most. And a few more have them at a decent enough price but only as a wheel/tire package with some tire I don’t want or need.

They are sitting in the Texas warehouse and there isn’t a service number or a contact on the Enkei site to find some relief.

These are the spec I want and they actually have them. They are also 25 lbs.

Still, I don’t know these people and they haven’t a web presents. I feel a bit stuck.

I put in a request at Tire Rack to look into a special order. I'll see what that turns up before I give up on Enkei.

This happens all the time with nearly everything I try to order. Why is this so hard?

Grumpy Bear · March 20, 2017

20K Report Card.

Pinion leak. Yes this is a warranty issue and NO an authorized GM dealer will not get within a bow shot of this truck. Friday this will be taken care of by someone who cares about more than “booked hours” done on GM’s discount. Alignment. Yep needs one and we ran out of time today to get to it. Friday. In early post I complained about harshness when hitting square edged bumps like a bridge approach. Well I wonder why. Note as well that I observed the shoulder wear which is also partly a caster function when the amount is a bunch. We also have a toe issue (the root cause of the steer ahead) and some moderate thrust angle. Even though it is in ‘spec’ it is not in my spec. Front Caster Effects

Effects of Positive Caster

excessive caster will cause a high level of road shock to be transmitted to the driver when the vehicle hits a bump,

Effects of Caster on Tire Wear

With a high amount of positive caster, the camber changes that occur, especially at low speeds in tight turns, cause the tires to show wear on their shoulders.

We did the oil change and tire rotation and noted a cluster of rock chips…you guessed it…leading lower edge of the box. So much for the factory ‘rubberized chip guard’.

With 5K on the oil change the OLM showed 31% remaining.

Edited March 21, 2017 by Grumpy Bear

Grumpy Bear · March 21, 2017

Fixed the paint chips in the box today. Mid 60’s F which isn’t warm enough long enough to put on the chip guards.

http://www.aligncraft.com/terms/terms.html

Above link is a decent reference I thought I’d share.

Tire Rack answered my inquiry about the ST6 Enkei wheels and yes they can order them but haven’t answered the lead time or weight questions as of today.

Added another X-Gauge to the Scan Gauge II package. EOT. Estimated Oil Temperature. So we of course go for a ride.

64 F Air Temperature.

67 F Inlet air temperature

189 F Trans fluid temperature

204-207F Water Temperature.

224 F Estimated Oil Temperature

60 MPH.

Grumpy Bear · March 21, 2017

Knoweldge isn’t stagnate. I posted recently in Quantum Leaps (Off Topic Forum) that oils life is cut in half for every 20 F over 220F. It’s been the thinking for decades. When I was a younger man that number started at 240F. Anyway, newer informaiton has recently (to me) come to light. The entire article can be read at:

http://machinerylubrication.com/Read/475/oil-breakdown

It says, in part, that for ever 18 F over 165 F the rate of degridation doubles. Ouch! That is pretty low and it is for MINERAL OIL. Conventional non-synthetic oils.

On another topic:

In the graph the point of convergence is 225F which is also the operating temperature of the oil in my 4.3 liter Ecotec3 engine.

Although the motor spec calls for 5W30 it is feed a diet of 0W20 Quaker State. The viscosity at this temperature is less than ONE centistoke different. 0.6 cSt to be exact. If I could take just 10 F out of the oil temperature the viscosity of the 20 weight at the cooler temperature would be twice that of the 30 weight unregulated.

Viscosity slopes are linear. If you know two points of the curve you can calculate any other point you like. The flatter the angle the greater the viscosity index.

That number on the contianer you call viscosity isn’t viscoisty. It is grade. To meet a grade a lubricant much have a viscosity that falls within a range at a given temperature. A range of viscosities the grade must meet to be labled such. The actuall number varies as can be seen in the three of the same range offered on the graph.

Manufactures are attempting to meet some impossible government mandated fuel efficiency numbers. Low viscosity helps reach those numbers. Problem is high heat shortens oil life. Even synthetics. To compensate they are increasing oil volumes to unbelievable proportions. The thinking is more volume has more additives which take longer to deplete such as acid neutralizers. Which would be fine IF the oil were not so hot as to promote rapid oxidation which makes that point mute. The result is; I still change oil as often as I did before but it cost more and takes more. Manufacturing gets what it wants and I get to pay for it...again.

Grumpy Bear · March 21, 2017

The alignment chart in post #147 for reference.

I meticulously set the tire pressures this morning. By my analog dial gauge 32.5 psig knowing that this gauge reads one pound lower than the trucks TPMS and also knowing that it rounds by the standard rules of math. Meaning that the TPMS screen reads 34 psig afterwards.

Then we go for a drive on the highway and let things take their course. This snap shot below the result of that effort.

As mentioned in post #147 excess positive caster works the outside rib hard on both wheels. But the right front is also being aggravated by excess negative toe while the right front has some counter force in the form of positive toe which act to nullify each other. Add the negative thrust angle placing extra force on that right front and some negative steer ahead asking for a left hand turn that requires some correction and the result is a 3 psig increase in tire pressure due all the added heat. The other tires are singing along cool as a cucumber at plus 1 psig. It is a 50 F day and my pace never exceeds 55 mph.

With this trust angle the truck is being drug sideways 12 feet per mile!

At their maximum spec 37 feet per mile. And GM is good with that. Me, not so much.

Your TPMS is good for more than telling you if you have a leak or a flat, eh?

My drive is east west. The right side of the truck gets the sun. This will increase tire pressure 1.5 to 2 psig by late morning. You have to be aware of everything.

While I'm writing. This thread is my truck log and these are more notes to myself than any attempt to tell anyone anything. Still I hope some find the information useful enough.

Edited March 21, 2017 by Grumpy Bear