Gear Ratio (rant)

TxTruckMan · May 23, 2017

On your RPO list in the glove box, it should say either

GU4 - 3.08

GU5 - 3.23

GU6 - 3.42

and GT4 if it has 3.73's

But other than those four, GM doesn't give us crap for choices!

16LT4 · May 24, 2017

The reason the Ecoboost towed better is that it also has more balls than the 5.3. The 5.3 isn't 400 hp but around 360, coupled with the bloated weight of the half tons put it in the same power to weight as the plastic fantastics of the first LS powered trucks. The 5.3 isn't exactly a great truck engine, either, compared to the old Vortec 350.

OMG you lose speed going up a hill towing a trailer...it's called towing. Get over it. My '84 with 110 hp V6 has to drop into 3rd from 5th when towing 3000lbs too, and that's got a 2.73. People think you need a damn 1 ton to tow a bass boat these days.

The truck is geared for how you use it. As you said you don't tow much, the truck is geared for how you use it most of the time. With 4.10s, sure you'd tow better a couple of times, but then be crying about 13 mpg every other day you drive the truck. Personally, I'd rather take the fuel hit a few times towing than every day, especially considering the buy-in price for a 4.10 option. The numbers don't work.

Could always get the 6.2...

dman1458 · May 24, 2017

OP....Have you towed the same combo, same roads without any wind? I would be curious of the outcome. Chances are the wind played havoc on the computer and the truck was just trying to keep up. Did you try using manual mode and lock it down into a higher gear?

As for the wrong gears and choices and all, GM, I think just tries hard to fit the 90% rule. 90% of owners will want this and go with it.

KARNUT · May 24, 2017

When I carried lots of stuff my 3/4 ton rode like a half ton. When I move to more sales,demo, training stuff l didn't want to drive an empty 3/4 ton for the ride. The cure for me was gearing and gear venders, for the times I was carrying loads. That was back in the low HP 4speed days. That being said I would never be afraid of the tack hovering around 3K carrying or towing a load for 1/4 of the trucks overall life. I can recall hauling hay in the 70s with duallys and pulling the detant (passing gear cable or rod ) so the the turbo 400 trans would stay in third. When we needed second we manually shift. And rebuilding the trans was common at 60K miles till synthetics came along. The other option was granny 4 speed, no thanks. That's was with a 456 gear. Never had engine problems and they weren't stock, at 100k the body rot retired the trucks.

Havvkeye · May 24, 2017

I have one at work and we have side by sides for riding the pipelines and I can't think of one time I ever said "man, this thing sure pulls good"

From this post I am reminded of the "Derek Zoolander center for children who can't read good and want to learn to do other things good too"

Cowpie · May 25, 2017

But other than those four, GM doesn't give us crap for choices!

That is one of the reasons, among many, that I gave up my 1500 went with the 2500. I have been fond of 4.10 in many vehicles over the years and that is whet I have in my 2500.

JimCost2014 · May 25, 2017

So this is your first post?

I just don't find parts of this story all that believable.

BTW, for what you say you typically do, 3.23 gears are just fine.

Thank you, was waiting for someone to catch the 3.24 gears. Rants are better when you know your truck.

JimCost2014 · May 25, 2017

I have 3.42 gears? Is that any good or should I be angry too?

Had the 3.42 in my 14 with the 6 speed and 6.2. It was a rocket, hauled butt for a truck. Good ratio, just not as good mileage as the 3.23 or 3.08.

diyer2 · May 25, 2017

Lots of opinions, I will look at it this way.

The truck didn't burn excessive amounts of oil, the trans help up, the brakes worked etc. and it didn't leave you stranded on the side of the road.

Nanotech Environmental · May 26, 2017

Just drove a 300 mile trip in a 2017 Silvy 4x4 with 5.3 and 3.08. It had plenty of getup and go & would easily outpull my 06.

I didn't even drive for fuel mileage, as the traffic, time and weather conditions just wouldn't allow it. I was being a bit aggressive quite often & had decent headwinds, about 800lbs payload & a fair number of moderate hills, stop & go, and some city traffic as well. I still got 19mpg US(23 mpg cdn) on the trip. My 06 could never get that kind of mileage when driven that way. It would have got maybe 16-17 mpg US at best.

If traffic conditions were better and I had the time to see what kind of economy I could get, I have no doubt I could have broke 25 or 26mpg US

Honestly, I think some guys are being quite unrealistic when it comes to these trucks. With the power these have, 98% of buyers would be nuts to go with gears any lower(higher numerically) than 3.23 or 3.42 at most. 3.73 is really too much for most and 4.10 would just be stupid(with very rare exceptions).

My next one will be spec'd with either a 3.23 or 3.08.

16LT4 · May 26, 2017

I'm curious if and how my fuel mileage would change with 3.23s over 3.42s. Part of me says it would increase, but then part says it would decrease because the truck wouldn't have enough balls in V4 to push it at 75. The truck currently gets its best fuel mileage around 75 mph, but this is temperature dependent: between 60-65*, fuel mileage at this speed is optimum because it spends 90% of its time in V4. If the temp is above 80*, however, it barely spends any time in V4 mode at that speed, because the air isn't dense enough to make enough power on 4 cylinders to push the truck. 60* seems to be the happy spot between pushing through air density, that air density's effect on HP, and that powers ability to push the truck at 75 mph.

Silverado Steve · May 26, 2017

Based on inputs from those with the 3.08 versus those with the 3.42 with the 5.3, i doubt there would be much if any mpg difference betweeen 3.23s and 3.42s.

Cowpie · May 26, 2017

Just drove a 300 mile trip in a 2017 Silvy 4x4 with 5.3 and 3.08. It had plenty of getup and go & would easily outpull my 06.

I didn't even drive for fuel mileage, as the traffic, time and weather conditions just wouldn't allow it. I was being a bit aggressive quite often & had decent headwinds, about 800lbs payload & a fair number of moderate hills, stop & go, and some city traffic as well. I still got 19mpg US(23 mpg cdn) on the trip. My 06 could never get that kind of mileage when driven that way. It would have got maybe 16-17 mpg US at best.

If traffic conditions were better and I had the time to see what kind of economy I could get, I have no doubt I could have broke 25 or 26mpg US

Honestly, I think some guys are being quite unrealistic when it comes to these trucks. With the power these have, 98% of buyers would be nuts to go with gears any lower(higher numerically) than 3.23 or 3.42 at most. 3.73 is really too much for most and 4.10 would just be stupid(with very rare exceptions).

My next one will be spec'd with either a 3.23 or 3.08.

Yeah, what one has in mind to do with their pickup has a lot of play in what ratio works out the best. I have found that 4.10 has done exceptionally well in a lot of pickups I have owned over the decades. Just an all around great ratio for my needs. Hasn't really been much of a negative in the fuel economy area either. But for any kind of serious work, 4.10 does a wonderful job.

To be fair, the lower ratios in the bottom gears on the 8 spd compensate for that to some degree with taller diff ratios like 3.42, 3.08, etc, but it is just compensation one ratio for another. Starting ability in a tough situation can still be a problem with tall ratios compared to short ratio diffs, especially if one has that tough pull in soft ground situation. For a pickup that pretty much spends it's life on hard surface, the taller ratios may do just fine.

Even with 4.10 in my 2500, I typically am not higher than M5 on the 6 spd trans most of the time. Yes, even on stock rubber. Can't even imagine something like 3.08. I deal with a lot of curvy, hilly rural two lane roads and gravel frequently, so that is the reason I typically keep the trans from going into top gear, to limit gear searching and shifting frequently on every little hill. On gravel, I am rarely higher than M4. And i have to deal with 2 miles of gravel, minimum, every time the pickup leaves the driveway. Only on interstate or similar do I allow it to go into top gear, and that is, maybe, once or twice a month. All of this is why I found myself inventing new swear words about the 3.42 ratio in my 1500. I had to get rid of that pickup.

Nanotech Environmental · May 26, 2017

I'm curious if and how my fuel mileage would change with 3.23s over 3.42s. Part of me says it would increase, but then part says it would decrease because the truck wouldn't have enough balls in V4 to push it at 75. The truck currently gets its best fuel mileage around 75 mph, but this is temperature dependent: between 60-65*, fuel mileage at this speed is optimum because it spends 90% of its time in V4. If the temp is above 80*, however, it barely spends any time in V4 mode at that speed, because the air isn't dense enough to make enough power on 4 cylinders to push the truck. 60* seems to be the happy spot between pushing through air density, that air density's effect on HP, and that powers ability to push the truck at 75 mph.

It will easily have enough balls in v4 at 75, but it depends on a few factors. The 5.3 can put out probably as much as 150-160 hp in v4 mode & probably does about 1/2 that at 1500 to 2000 rpm. There are a few times that the truck would need about 80hp or less to maintain 75mph; Flat ground, or downhill. No headwinds. Light payload. If you reduce speed a bit, it would drop the aero load noticeably & go into v4 even more.

With the 3.08 version I drove yesterday, it went into V4 a number of times when I didn't think it would & that was at 75mph.

If this version was driven across the Prairies at 65mph with a tailwind, it would probably get about 30mpgUS, maybe more.

I guarantee that your truck will get better fuel mileage(longer term average) at 65mph than it does at 75.

16LT4 · May 26, 2017

It will easily have enough balls in v4 at 75, but it depends on a few factors. The 5.3 can put out probably as much as 150-160 hp in v4 mode & probably does about 1/2 that at 1500 to 2000 rpm. There are a few times that the truck would need about 80hp or less to maintain 75mph; Flat ground, or downhill. No headwinds. Light payload. If you reduce speed a bit, it would drop the aero load noticeably & go into v4 even more.

With the 3.08 version I drove yesterday, it went into V4 a number of times when I didn't think it would & that was at 75mph.

If this version was driven across the Prairies at 65mph with a tailwind, it would probably get about 30mpgUS, maybe more.

I guarantee that your truck will get better fuel mileage(longer term average) at 65mph than it does at 75.

Yes, the main variable being the amount of hp produced is dependent upon air temperature. At 65, my truck rarely spends time in V4, where at 75 it does, as stated. Pulls right up small inclines at 75 that at 65 would have it going to V8. As I said, after 11k miles of data collection, 70-75 mph is the sweet spot at 60*. 50-55 mph is the sweet spot at 35*. 65* is the sweet spot at 80*. The "sweet spot" being optimum fuel mileage. Data runs being the average between head-tail winds, north-south, east-west, etc.