The new 5.3 doesn't like to be babied! Shes alive!!&#3

TYLERZ7180 · January 15, 2014

Tonight on my drive home from work I was cruising and wondering why i'm only averaging 13-15 MPG. Since the day I bought the truck I babied it and did a bunch of slow acceleration to get up to speed. I kinda got frustrated with it and started driving it like my old lifted 5.3. I started pushing it to 3000-4000 Rpm to get it up to speed, I wasn't gunning it but driving it pretty hard. Well what do you know...the motor loved it and she opened up to me!!!!. I kept driving and jumped on the highway for some MPG tests. I punched it and passed a Semi and let it settle to 65/70 and she purred and my MPG went through the roof. I love it!!! I'm now averaging 18-20!!

To be noted...I have a the All terrain double cab 5.3 with the 3.43 rear. (890 miles so far). Anyone please jump in and comment about what you think. I'm now driving her like my last truck for sure!

Painter1992 · January 15, 2014

I'm going to have to try that. I can't get an average above 15.9 mpg. I get worse on the highway than in town.

TYLERZ7180 · January 15, 2014

I'm going to have to try that. I can't get an average above 15.9 mpg. I get worse on the highway than in town.

Are you taking it easy on the motor and watching your instant MPG screen??

mike94silverado · January 15, 2014

You calculating it by hand or computer?

Sent from my iPhone using Tapatalk

JCthebigTree · January 15, 2014

I'm coming up on 2,600 miles and I'm starting to see my MPG improve to 13 or so. To be fair, it's warmer than it has been and that's helping, but I was getting piss poor milage for awhile. I haven't really babied her since about 500 miles.

I have been playing around with driving in M... I'm noticing at 55 MPH, I actually get better MPG (according to the DIC) while driving in M5 than in M6 or D.

I've also noticed that it seems like I actually get LESS mpg while in V4 than in V8...need to test this more though.

LTZTom · January 15, 2014

My 2007 5.3L NEVER got better than 13-14mpg around town and about 16/17mpg on the highway. When pulling my 14' motorcycle trailer it got 10/11mpg. That's one of the reasons that I got a 6.2L in my new truck...I figured since I was used to sorry gas mileage it would probably wouldn't be much worse. My 2007 was 6½ years old when I sold it and had only 19,000 miles on it so I don't really drive enough to care how sorry the gas mileage is. Honestly, I really do care but nothing can be done about it I guess so I'll just live with whatever it turns out to be.

Here's the last picture I took of my old truck on the day I sold it.

amxguy1970 · January 15, 2014

It's funny you mention that, break in of a motor really isn't necessary when you purchase a new vehicle. The big reason they tell you to take it easy from jack rabbit starts/stops, ect is for the other parts of the vehicle (drive line, suspension, brakes and so on). There is a ton of shock to new parts spinning the tires and taking off like a bat out of hell from a redlight. The motor though does need to "unwind" so to say. The old C5 Z06 would develop oil consumption problems mostly from never being driven hard and not allowing the motor to loosen up.

When I bought my GTO I searched and searched on break in proceedures considering my car had less than 15 miles on it. So what did I do? First 200 hundred miles I would take it up to 4k rpm, next hundred 5k rpm, then redline after 300 miles. All this on the highway to save the drivetrain the shock.

How did the car respond? If you search LS2GTO I had the highest stock dyno GTO 359/366 on a 71 degree day at a mustang shop (had only a hp or two difference with correction factor). Cruise set at 70 averaged 28.6 from madisonville to corsicana TX and ran thru the traps at 109 stock.

Ponit is babying it usually isn't the best and the motor won't properly seat everything. Plus it needs to learn the style too. When you are on the highway do a few pulls to 5k in the first few hundred miles, let the motor rev and learn.

http://mototuneusa.com/break_in_secrets.htm

This was one of the final websites that showed me why to break in a motor harder than softer. Many other people say the same thing. There is a reason new motors are strapped to the dyno by engine builders. Shoot, this is a no brainer for anyone who has been to Maranello. A test driver runs the everlivinghell out of every car. Then, they put on new tires/wheels and reset the odometer. Every new Ferrari is run harder before delivery than most will ever be run. The factory has always believed in a ballstothewall beark in. Therefore, it makes since that a new replacement Ferrari engine should be run HARD. I have always heard that a car broken in slow will be slow. Also, newer car computers do defintly have a memory for driving skills.

Most engine builders say the same thing, run it hard after warming up. Also always vary the speed in the first few hundred miles, never cruise at a constant for long periods.

Maybe that is the reason some people have had oil consumption problems on the older afm's? They just babied it and it didn't seat/break in correctly?

Tyler

Charlie5280 · January 15, 2014

Really it has to do with static friction. The most efficient way to drive a car actually it booting it within it's peak torque/efficiency range, then allowing kinetic energy and inertia to keep the object in motion........as "An object in motion tends to stay in motion".

This is why Hybrids get such better MPG in the city. They use the electric motors torque to break that static friction, then coast essentially.

TXGrantDuke · January 15, 2014

I've put about 1,000 miles on my 14 Silverado. 5.3L. With just city driving I get about 15mpg. I try not to gun it too much (certainly not as much as I'd like). Anytime I put 10 or so highway miles on the average for the tank jumps up well over 16. It seems to love 65-75 mph.

PaulM · January 15, 2014

Tonight on my drive home from work I was cruising and wondering why i'm only averaging 13-15 MPG. Since the day I bought the truck I babied it and did a bunch of slow acceleration to get up to speed. I kinda got frustrated with it and started driving it like my old lifted 5.3. I started pushing it to 3000-4000 Rpm to get it up to speed, I wasn't gunning it but driving it pretty hard. Well what do you know...the motor loved it and she opened up to me!!!!. I kept driving and jumped on the highway for some MPG tests. I punched it and passed a Semi and let it settle to 65/70 and she purred and my MPG went through the roof. I love it!!! I'm now averaging 18-20!!

To be noted...I have a the All terrain double cab 5.3 with the 3.43 rear. (890 miles so far). Anyone please jump in and comment about what you think. I'm now driving her like my last truck for sure!

ooooooooooooooook, you think 3000-4000 is getting on it? The thing will rap out to 5500, let the thing breathe, its a machine man, that can do that, not a 16 year old mule with 3 legs

fondupot · January 15, 2014

my mileage is around 16 mpg. The majority of my driving is around town with lots of lights, turns, stop signs etc. I could probably do better, but winter blend gas hinders some.

I'm sure it will get better in the summer.