Improving Mileage - Which is best?

[brufener]

Hello:

 

I just picked up a 2001 Chevy Suburban (1/2 ton), and sold my 1999 Chevy Blazer. Although I have only put one tank of gas through it, I have been surprised that the mileage is significantly worse than my blazer. In mixed driving my blazer got 15, while the suburban gets 11. The blazer got 12 city, and 18-20 highway (running 87 octane).

 

What should I start with in order to improve mileage? All the maintenance has been kept up on this truck. It has been 27k since the fuel filter was changed. The truck is stock, 5.3L, stock 16 in wheels/tires.

 

The truck has a 4.10 rear end, I don't tow much (maybe once or twice a year). Would it be worth it to swap out the rear end to a 3.73 or a 3.42?

 

I have heard about getting a PCM tune, how much do these really help?

 

What about upgrading the intake and/or exhaust? Worth it?

 

Which one of the above should I do first?

 

No I haven't been hot-rodding it any more than I hot-rodded my Blazer. I'd like to investigate the above and leave my driving habits alone.

 

Thanks,

 

Bryce

[Bish]

Hello:

 

I just picked up a 2001 Chevy Suburban (1/2 ton), and sold my 1999 Chevy Blazer.  Although I have only put one tank of gas through it, I have been surprised that the mileage is significantly worse than my blazer.  In mixed driving my blazer got 15, while the suburban gets 11.  The blazer got 12 city, and 18-20 highway (running 87 octane). 

 

What should I start with in order to improve mileage?  All the maintenance has been kept up on this truck.  It has been 27k since the fuel filter was changed.  The truck is stock, 5.3L, stock 16 in wheels/tires.

 

The truck has a 4.10 rear end, I don't tow much (maybe once or twice a year).  Would it be worth it to swap out the rear end to a 3.73 or a 3.42?

 

I have heard about getting a PCM tune, how much do these really help?

 

What about upgrading the intake and/or exhaust?  Worth it?

 

Which one of the above should I do first?

 

No I haven't been hot-rodding it any more than I hot-rodded my Blazer.  I'd like to investigate the above and leave my driving habits alone.

 

Thanks,

 

Bryce

 

<{POST_SNAPBACK}>

 

 

 

 

First off, remember your Sub weighs a lot more than your Blazer and tips the scales at close to 3 tons and has an extra 2 cylinders to feed.

 

Having said that a gear change would help but not a lot. I have 373 in my Tahoe and I get 12-14mpg around town and it's a little lighter than your Sub. If you have 4x4, I doubt the increase in mileage would offset the cost of the gear change.

 

An intake and exhaust combo should net 1-2 MPG as it did on mine but then I tend to get "into" it a lot more 'cause it's more fun now and that offsets any mileage improvement. A custom tune may help but again, if you romp on it more, no gain.

 

Bottom line IMO driving style and speed has more impact on mileage than these changes. I can get 4-5 more MPG on highway by driving 65 instead of 85 I say get over it, it's a tank.

[brufener]

Hi:

 

Perhaps I should have added this disclaimer: I know that the Suburban is big, heavy, and uses a lot of gas. I did not buy it to be a fuel efficient vehicle. I will not sell it because it gets poor gas mileage.

 

On the other hand, if I can get better gas mileage and still drive the Suburban then there is no reason for me not to do it. I asked the question because my suburban seems to be getting lower fuel mileage than what other people have posted. It seems that most suburbans got about what my blazer did, if not slightly better.

 

Thanks,

 

Bryce

[emitsTech]

I'd make sure your O2 sensors are good and maybe check spark plugs/wires and check the stock air filter (or pickup an aftermarket ) and possibly consider an exhaust system. But I'd only expect 1-2 mpg increase like Bish said above. Just my $0.02.

[BlueTahoe]

I got a decent MPG increase from a new tune. About 2 mpg. Most people I have seen on here get a 1-3 mpg increase with a mail order tune.

 

I did the math on mine similar to the below calc.

 

20,000 miles @ 11 mpg = 1818 gallons - $3,636.36 @ $2 gallon

20,000 miles @ 13 mpg = 1538 gallons - $3,076.92 @ $2 gallon

 

in 20,000 miles in this scenario it is $559.44 savings. So if you plan on putting some miles on it I feel the tune pays for itself. Oh and it runs MUCH better than stock.

 

I'm very happy with my westers tune. The best investment I have made for my Tahoe.

[silver-rado]

I agree the Wester's is your best bet. combined with an intake.

[Tucson_02Silverado]

Stock 2001 Suburban with 5.3L @ 11MPG

 

That's more like a Sub with an 8.1L.

 

It's supposed to be average rated 14-18MPG with a 5.3L

 

Something is wrong.

 

27K for fuel filter is much too long. Most here go max at 15K, some here change at 6-10K.

 

 

First do's that put you in a very good start point.

1. Check all hoses, especially vacuum, for cracks/leaks.

2. Check ECM for any codes that have been thrown.

3. Decarbonize the engine.

4. Change all fluids and filters. Wait for this after #3 as the oil gets contaminated from the process.

5. Change plugs and wires.

 

At least for myself, those would be things I would do on any pre-own vehicle I've acquired.

[99-2door]

The fact that you got 12 MPG in your Blazer tells me it is your driving style.

Ease up on that throttle and you'll get better mileage.

[willieboy]

I would have to say easier on the throttle, and maybe trips longer than 1 mile and you will see an increase. My 'Burb get 13-14 in town, and most of my trips are 4 miles/10 minutes (between work and home). Now, I have the FFV 5.3l, but I doubt that makes much difference. I could also go easier on the throttle, but I won't, LOL...

[firefighteremt3100]

Most of you will probably think this is a dumb question...so I apologize to you in advance...since I dont know much about this, I am going to use it as a resource. What is this "Westin" "Custom Tuning" all about? Any information would be helpful. Thanks.

[100R1]

Gear ratio is hurting you

 

I have a Yukon with the 5.3 & 3.73 ratio I get 13.3 mpg city driving

 

I just got a tuned PCM from Wait4Me Performance for $ 150.00 If I can get the 1 -3 MPG improvement others are seeing, I figure that 2 MPG would be a AVG of what others are seeing, Then the $ 150.00 investment in a PCM will pay for itself in about 7,000 miles based on current gas prices.

 

If you want to maximize your fuel millage and performance in crease is not really what you want then specify a pure millage increase PCM re-tune. you will defently get better milage than you are getting now.

 

we are pushing 5,000 lbs plus hard to get great gas millage, but every little bit helps.

[03blackburb]

A couple of other things:

1. Check your air filter. By using a K&N drop in you should pick up a mile or 2 per gallon.

2. Engin oil. Switch over to 5W30 Full synthetic. This is usually good for a mile or 2 again.

Might not conside these as mods but rather routine maintenance. They can and do make a difference. You did not state how many miles you have on it. Might be time for new plugs and an upper intake cleaning also.

[Rammer]

Not knowing the terrain you drive, it is impossible to tell if a gear change would be worth it. If you live in a flat area and have no hills to climb, then agear change will help. In my area with all the hills, a taller gear will help fuel milage, as the engine doesn't have to work as hard.

 

Check your tire pressure, filters and unload anything you don't need to carry with you.

[DJinCO]

I have just returned from a 230 mile round trip to the mountains (for

fishing but didn't catch anything worth keeping, but that's another story)

after installing the "new" computer with a Wester's custom tune last night. My

power was phenomenal going up hill, the Tahoe just kept pulling. Great

throttle response. Cruised at between 65-75mph from 7000-9500 feet in

altitude; Blew past a ricer at 85mph going up Trout Creek Pass, had loads of power to pass and to top it off, I averaged 18.1 MPG for the trip which included stop-n-go in town!!!

 

 

I'm sold on a Wester's Tune.