2017 sierra gutless

Olds69442 · November 30, 2019

Sierra with 65,000 kms at about 16,000 I noticed fuel economy was very up and down. But it seems to be worse now.

The truck seems to require more power to move, like something in the front end is holding it back.

If you try and drive on dry grass or gravel it spins the tires. On wet pavement if you give too much gas the back end kicks out and traction control kicks in.

Just wondering if anyone else has come across this issues and know what is up. The dealer says no code everything is fine.

CamGTP · November 30, 2019

Fuel mileage can vary some depending on the season and driving habits. Extended idle times, using remote start, cooler weather etc etc can all play a roll. Mine is always 10-14mpg give or take because it's all shirt trip city mileage.

You'd know if something was dragging on the front. You'd smell the brakes or it would be a pretty noticeable pull when you let off the throttle, like if something in the front diff was an issue. And there would likely be a noise with it too.

Spinning on loose gravel or grass sounds normal. You tire choice may not be ideal or you just aren't as good with your big toe for feathering the throttle. Same with wet pavement, tire choice and your foot are the biggest factors.

The dealer is right though, if you have no codes or any actual faults, they can't really help you when it's still running like normal.

JimCost2014 · November 30, 2019

50 minutes ago, Olds69442 said:

Sierra with 65,000 kms at about 16,000 I noticed fuel economy was very up and down. But it seems to be worse now.

The truck seems to require more power to move, like something in the front end is holding it back.

If you try and drive on dry grass or gravel it spins the tires. On wet pavement if you give too much gas the back end kicks out and traction control kicks in.

Just wondering if anyone else has come across this issues and know what is up. The dealer says no code everything is fine.

Welcome to the site!

I am guessing by your site name, you are a little bit "older" like myself.

In high school, we judged how quick a car/human was by racing each other, my 73 Vega was pretty fast. Race your neighbor, you will feel much better about your truck!

I think you are experiencing the "hard to depress gas pedal" on your truck, you just have to get used to it, gas mileage will also vary with it getting colder too.

You are driving a very sophisticated vehicle with very powerful computers in control, it does the best it can with temperature, gas, and your driving habits to get the best mileage possible.

Olds69442 · December 1, 2019

Haha, how old do you think I am?

I own several 442's and restore them.

I guess it's too hard to explain my issues, from brand new the truck ran between 8 to 10 litres to 100 kms. Doing the same drive day after day once I got over 16,000 kms the mileage seemed to jump up as high as 17 litres but time to time no matter the temperature outside. Over time it keep happening more often, now it's all the time.

At times I could feel the truck change as I was driving, and see the mile go up higher too.

This would be my third brand new GM truck having 2007 and 2010 before so I'm sure to this newer technology.

This truck has been in seven times for repairs and warranty work and the dealer finally got the new code off the truck that kept going off on friday and it have a fuel trim code.

I'm to the point I think it's best to sell it and look at a different auto manufacturer since the 2010 has oil consumption issues and the 2007 had electrical issues. GM does not build good vehicles and when its shit they dont stand behind repairing there problems. It's all let's reprogram and see if that works until your warranty runs out and it's the consumers problem.

L86 All Terrain · December 2, 2019

You should not spin when driving across even wet grass in 2wd. Something is hanging up in the front. Jack it up in there and spin the tires by hand. Dragging brake? Wheel bearing packing it in slowly? Sometime the sliding pins for your calipers will seize up and the brake will be slightly dragging at all times until you pull them out and re-grease or replace them.

How many miles? These new DI engines have a habit of caking the intake plenums and valves with carbon. Much much worse than the LS's port injected engines. If you have a lot of miles it could be due for a walnut blasting or at least an intake cleaning additive. Winter time in Canada now, idle time, colder IAT's, thicker oil viscosity in the trans/diffs lead to more resistance and longer warm up times, winter gas at the pumps, longer warm up times really take a toll on your economy.