sheadmo

i have a 2011 truck best mpg is 15.2 on hwy went chevy to fix they said it got 19mpg ithink they are full of ---- cause i have over a1000.00 of receits that all come up with 15.2 mpg

ericnottelin

guys you are forgetting one big important thing. Gear ratio. For example, most of your trucks (like mine) come with 3.73 or 3.42 rear ends. A buddy of mine had the 3.06 rear end. Now he got 19-20 mpgs all day long. One day, I drove his truck. down the interstate at 75 mph, his truck was between 1500 - 2000 rpms. Where my truck hits 2000 rpms at 70 mph. So his motor is running almost 500 rpms less than mine to do the same speed. Now, I would NOT want to tow my 8k camper with his truck with that 3.06 axle. That transmission would explode

So, if you are never going to tow with it or haul heavy loads, make sure you get the lower gear ratio and your fuel mileage will be up there.

For those of us that either tow or like to jack up the trucks and need the taller gears, were should just suck it up.

In regards to the epa ratings, think about this. If you are a GM engineer and they say, we need a few of your trucks to verify your fuel mileage estimates, which rear end would you give them? I bet every one of those trucks that were used to get those EPA estimates, had the lowest gear ration that GM offered. Thats what I would have done.

Chevrolet Customer Service

<!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:PunctuationKerning/> <w:ValidateAgainstSchemas/> <w:SaveIfXMLInvalid>false</w:SaveIfXMLInvalid> <w:IgnoreMixedContent>false</w:IgnoreMixedContent> <w:AlwaysShowPlaceholderText>false</w:AlwaysShowPlaceholderText> <w:Compatibility> <w:BreakWrappedTables/> <w:SnapToGridInCell/> <w:WrapTextWithPunct/> <w:UseAsianBreakRules/> <wontGrowAutofit/> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> </w:WordDocument> </xml><![endif]--><!--[if gte mso 9]><xml> <w:LatentStyles DefLockedState="false" LatentStyleCount="156"> </w:LatentStyles> </xml><![endif]--><!--[if gte mso 10]> <style> /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} </style> <![endif]--> The 2011 Silverado 5.3L, 8 cylinder, 6-speed automatic averages 15mpg city / 21mpg highway / 17mpg combined.

However, MPG varies person to person. You have to take things into consideration, like driving habits, maintenance, service, etc.

Louis
GM Customer Service

sheadmo

my driving habits havent changed in 40 years i drive the speed limit on hwy,i have heard every excuse from chevy,ido not drive on perfect track conditions i drive in the real world not fantasy land.15 mpg on hwy really sucks 15 to 22 is not a reality its a fantasy

jackrook

if it makes you feel any better, my 2012 2500 6.0 crew cab gets about 12 MPG on the highway. LOL

ericnottelin

In regards to my last post, what rear axle do you have. Also is it a 4x4?

ericnottelin

Oh crap, I just noticed something else. Your going to poop yourselves when you think about this!!!!

Sorry Louis, but the standard GM answer is going to be hard to explain this one!!

Ok, when you go to the government website that lists the fuel economy ratings (Fuel Economy), you will make an awesome discovery.

Ready for this!!

Ok, they only list the make, model, and year. So, the rating of 15 city, 21 highway, and 17 combined is for a 2012 Chevy Silverado with a 5.3L and a 6 speed tranny. Now the picture on the EPA website is of a crew cab. But there is absolutely NO (i repeat "NO") options for trim. So everyone, what weighs more a regular cab, extended cab, or crew cab. Let me help you .

All 2012 Chevy Silverados with 5.3.l 2wd with 6 speed tranny courtesy of Chevy.com

Regular cab curb weight - 4850lbs
Extended cab curb weight - 4885 lbs
Crew cab weight - 5099 lbs

So the regular cab to extended cab is not much. But the crew cab is 249 lbs heavier.

Now since Chevy can use any of these trucks, which one do you think they would use? Hmmm I would guess they used the lightest one they got -

Ok, since they can use any truck they want, the regular cab 5.3 has an available 3.08 rear end. Additionally, the skinniest tire offered for the Silverado is the 245/70/17 (skinny tire = less rolling resistance) which has a diameter of 30.5".

The final drive on the 6 speed tranny is .667:1.

So math here,

In 6th gear

W/ the 3.73 rear end @ 60 mph (which is what the EPA measure mpgs for highway speed) the engine is spinning 1650 rpms

W/ the 3.42 rear end (common in crew cab trucks) @ 60 mph the engine is spinning at 1500 rpms

Conversely

W/ the 3.08 rear end at 60 mph the engine is spinning 1350 rpms. That is 300 rpm difference from the 3.73 rear end.

Ok now for real life applications vs the epa truck, Our trucks (crew cabs) usually have wider tires (265 and 275 mm widths) which are much less fuel efficient. Additionally, the majority of us have (again for the crew cabs) either the 3.42 or the 3.73 rear ends.

3.08 @ 75 mph = 1700 rpms
3.42 @ 75 mph = 1900 rpms
3.73 @ 75 mph = 2050 rpms.

So in conclusion, we unknowing purchasers (until now) can not expect our crew cab trucks with those beautiful wide tires and towing gears will never see that 21 mpg that a regular cab truck with the shortest gears and skinniest tires available can get.

Sometimes I hate epiphanies.

Eric

sheadmo

2011 crew cab 4wd 6sd auto,373 gears,like i said at hwy driving 15.2 computer was ck out good all in specs so in your perfect world and mine are two different things bottom line is i was sold on mpg a little white lie chevy already has my money,same old song and dance untill i get tired about waisting my time ,i just want to get what i paid for not a fanatasy

ericnottelin

My point is that I was agreeing with you, to a point. You were sold a white lie. Because those great epa numbers are represent of a regular cab truck with 3.08 gears. When you add another 250 lbs for the crew cab, 3.73 gears (now the truck's motor has to spin at a higher rpm to go the same speed), and not to mention I'm sure you don't have the skinniest 245mm tires (which are the least rolling resistant of the tire sizes), your truck is going to get a much lower mpg than the measured truck.

What Chevy (and other vehicle manufacturers) need to do is give EPA estimates on all the different options available. So when you add that taller gear, or get the crew cab, or both, you are advised that truck will NOT get the MPGs that attracted us to the Silverado in the first place.

Mkenny71

If they are 3.07 I'd be interested in them. I'm dropping my Chevy for highway driving and experimenting with the other side of the spectrum. My friend has a charger with a stroked 440. He blew up his 4.11, 4.56, and 5.13. Hey swapped in the stock 3.0s and beat everyone's *** all day. I had questioned for years about H/P overcoming gearing yet no racers would answer the question. Then my friends charge stole the day. Guess I got my answer.