M P G in suburban

[Kaisen]

Irony is just about every piece of GM iron I've ever owned gets 14mpg. '80 Chevy Luv 4-banger, '73 Formula 400 Firebird, '85 C-10 with a carb 305, both Tahoes. And now the Sub. I'm a slow learner I guess.

 

[rayra]

wth is that, coasting downhill on a long grade? says Tahoe and looks shiny and new, what are the specs? And how low was the cruising speed?

/lol

 

[Kaisen]

wth is that, coasting downhill on a long grade? says Tahoe and looks shiny and new, what are the specs? And how low was the cruising speed?

/lol

I averaged 23.2mpg over a ~225 mile round trip this Spring in a 2015 Tahoe 5.3L 4x4. Constant freeway speeds at 62 mph. The 25mpg photo was of the first 20ish miles. It's very easy to get better than 20mpg, and I believe their official EPA rating is 22mpg for 4x4. I could get 20ish around town if I was gentle. Overall very impressive. I got even better fuel economy out of the 2014 and 2015 Silverados, even 23mpg freeway (same round trip) out of a 2015 6.2L 8spd 4x4 this Fall.

 

[bahndo]

I have a 2004 2500 and get 19-20 on the highway doing 70-75, and 15 around town. Mine has a 6.6l druramax from a 2007 2500 HD though.... I highly recommend this setup if you can get your hands on one.

 

[jerrysull2]

It gets 11 MPG in the city
It gets 11 MPG on the highway
It gets 11 MPG towing a boat
It gets 11 MPG hauling kids to soccer
It gets 11 MPG sitting in the driveway
It gets 11 MPG if you push it over a cliff

I get 11 MPG too.

That made me laugh. It also describes my old 5.7 perfectly! It also did 11 MPG.

I now have a '97 with a 6.5 in it. That gets a lot better, high teens in the city, 20 on the highway is the norm for me. A bit lower nowadays as it needs a tuneup.

 

[Erik N]

I have a '99 Suburban 2500 with the 7.4l

I once read somewhere on the internet....

It gets 11 MPG in the city
It gets 11 MPG on the highway
It gets 11 MPG towing a boat
It gets 11 MPG hauling kids to soccer
It gets 11 MPG sitting in the driveway
It gets 11 MPG if you push it over a cliff

I get 11 MPG too.

Exactly. My '88 gets 11mpg EVERYWHERE. Either on the freeway with a tailwind to 4 low 1st gear crawling. Amazing, really.

My 96 gets 11mpg on the freeway, but only about 4 in soft sand.

 

[98dango]

My 84 got 18 once from Breckenridge co to Grand Junction had a nice tail wind. The square just can't pull great mileage.

 

[Buddha.]

Sometimes I think about getting rid of the s10 blazer for a suburban. I like the ride better and I think it's be great to crash in the back on a camping trip. I get an average of 16, I got 19 once on a two hour highway trip doing 55. It was only $2500 though.

 

[southpaws3]

you can get an aftermarket 42 gal fuel tank replace the 34(??) one still fits inside the frame .but seriously we all know these beast vehicles are not fuel friendly. more/bigger fuel containers i guess we can get a prius put a luggage rack on it and pray we make it .pack more fuel and know we will

 

[7echo]

Seems like most of the trucks I want do not get the mileage I think I can live with. My '99 4runner 4wd gets around 15.5 in my daily driving duties. I imagine a Suburban would be at 10ish. My work truck, 2000 Tundra AC 4WD gets 10.5, but that is 99 percent in town, lots of stop and go, and rarely over 45mph.
It is more tempting lately with the gas prices around $2/gallon, but that can't last.

 

[Moab]

My current 1990 1500 gets 10-12 with a tired 350. My old 1990 2500 with a new replacement 350 with a roller cam and vortex heads got 18-20...20 was driving 65 in traffic (drafting) but 16-18 was very typical. I don't know if the engine was the only difference causing the mileage change. Everything else was basically stock. Both were TBI etc. I almost never tow anything heavy or fast so a bigger engine isn't necessary.

I wonder if you could build a 350 that would do much better on fuel? What would you put on it ? I have wondered about the newer 4.3's. Their power is similar to my 190hp '90 350. Summit sells a crate 4.3 with something like 250-275hp.

Fuel efficiency isn't everything but it does weigh on my mind when deciding wheather or not to take the long way.

Matt

 

[warwgn]

Here is my milage, 86 3/4 ton Suburban, 496 CI, Q-Jet 800 CFM, 4L80E trans, 208 T-case, GM 14 bolt semi float with 4.11 gears, and running 37" military OZ tires.

not to bad for what it is, but sure need to get the bug done before gas goes back up, Subzila is not ideal for daily commuting but I have enjoyed driving it every day.

 

[fishon1213]

I have an 86 3/4 ton 2wd with the 5.7. haven't had it long but so far I am getting 10 city/14 highway. Its running rich though and has smaller tires in back than it should have.

 

[k9lestat]

99 1500 5.7ltr no matter how i drive it I get 13 mpg

Sent from my QMV7A using Tapatalk

 

[highlandercj-7]

If you want stock driveline in a Suburban platform that performs well, we got the best performance out of our 01' Denali XL 6.0L. It easily pulled 18 MPG around town and 20 MPG on the road. I towed a Club Car Diesel 4x4 golf kart with the full cab, bucket and all on it sitting on a 18' car trailer and got 18 MPG over a 200 mile trip.

We only got 10 to 13 MPG at best out of our K5 Blazers and K10 trucks, in all configurations. 78-91 and we have had around 20 of those old Chevys and GMCs. The 97 Vortec 350 4 dr Tahoe only pulled about 16MPG at best. The 93 6.5L Diesel was about 18 MPG unloaded.

I'd put a 6BT Cummins in the old body style GM for the best MPG and performance. My dream truck is a 87-91 or a 92-94 Chevy Crew cab with a Cummins 6BT and NV4500.