Chevy 350 fuel mileage

[Camstyn]

We've got a borrowed van right now, until our new one arrives. It's a new '02 GMC Savanna, heavy duty 3/4 ton with the 5.7 engine. I figured it would get better mileage than it does, so I figured I'd ask what others are getting. At best it will get 19mpg (imperial gallons, would be 16mpg in US gallons). All highway driving, it's got 14,000 km's now and it's a month old. Is this normal?
The previous van we had (1997, same van but extended wheelbase, 1ton, 6.5 diesel) got between 23 and 24mpg (also imperial, works out to about 20mpg as per US gallon measurements).
Anyone driving a truck or van with a 350 care to comment on their fuel mileage?

 

[Highbeam]

Mine is great. 98 350 vortec in a half ton 4x4 fullsize pickup with an auto and a fiberglass canopy. Low of 15.5 around town in winter. I got a tank of 18.7mpg (270 miles, it was a personal record) on the 4th of July with a lot of highway cruising at 65. Mine gets much better mpg when the weather is warm/hot. That same drive would have gotten me 16.5 mpg in the winter. I keep things clean and maintained and have stock tires and no lift. 65,000 miles. I always use chevron regular fuel.

These mpg figures compare very well to others such as dodge ford and even toyota. The mpg is one of the main reasons I got the chev fullsize.

 

[Milquetoast]

I have an older Chevy conversion van with the 5.7L and auto trans with overdrive. I would love to enjoy 16mpg from the van, but usually it gets more like 13 or so on the highway.

 

[YZ Joust]

I get around 17/18 mpg in my 99Tahoe (5.7 Vortec)..... Not too bad.... ;)

 

[jeb]

I've had 350's in 2 newer 4x4 suburbans. Somewhere near 16mpg was about right for highway cruising. I had a 454 in my 99 'burb. 13 was the best I ever saw for unloaded highway cruising. My duramax diesel gets 21-22mpg in the same situation.

 

[yo its matt!]

its normal to see higher mileage numbers on diesel vs. a gas but it takes alot of miles to make up for the cost difference on the diesel option, dont feel bad my 02 hd2500 with a 6.0l only gets 14 thats towing highway, city, maybe would get a little better if i drop it off a cliff but i dought it!

 

[Rodzilla]

How'd you get a 5.7 in a 2002? At least in the states you can only get the 5.3 or the 6.0 (or the 8.1 for the big trucks) at least in the truck line, I have a 99 with the 5.7 Vortec and get about 16 as well.

Rod

 

[splatt]

Thirteen mpg or better from a 350 Chev. I wish I was able to get 10 mpg out of my 77 Blazer. Oh wait now I remember why it has about 300+ hp and other non-gas mileage depleating mods but oh what fun it is.

Steve

 

[biglou]

I've got a 97 extended cab short bed 2WD with the 5.7 and I get right at 17 MPG with about 75% highway driving. I thought that was pretty good, myself!

 

[Camstyn]

With the full sized vans, they are still using the old engine configuratoins.. including the 305, 350, 6.5L diesel, and the new 8.1 gasser.

It does take a while to pay for the diesel engine, but this van does a lot of driving and the fuel savings work out to a figure just shy of $400 per month, over what the fuel bill would be for gasoline. This pays for the engine rather quickly, plus it's highly unlikely that we would get 5 years life out of a gas engine, it will have accumulated close to 700,000 km's by then. The diesel should have less breakdowns and be cheaper.

 

[Highbeam]

Cam, you are the perfect candidate for a diesel. Your driving habits are ideal for a quick payback on those initial costs. Good choice.

 

[Tony Eeds]

I have a 2001 4x4 Surburban that I am currently driving. It is 16 months old and has slightly over 65K on the odometer. I love the truck, but am well aware that I am driving it into the ground. It gets good (17+) mpg overall because 90+% of my driving is highway.
I am thinking about a new HD 4 door short bed pickup to split the mileage up between two vehicles. Sometimes I need a Surburban for clients but often I am carrying stuff that would haul better with a pickup. (Bikes) :)
Is the diesel a good choice? Everything I have read says the new Isuzu engine in the GMs is great.
I expect to keep both until there is about 250K on the odometer.

 

[GETMETOCA]

I get about 16 mph HWY with my '89 Chevy Silverado 350. More like 14.5 with stop and go around town. For an older vehicle it still gets decent gas mileage compared to when it was new. I was getting about 18 then.

On my trip to Oregon in May, I got 14 mpg avg. 956 miles round trip. That was with three bikes, three bodies, 3 sets of gear and one tool box. I did not think that was too bad.

 

[Highbeam]

Tony

Yes you are another great candidate for a diesel. If you run the truck to 250k miles, fuel costs alone will justify the diesel upgrade. I must warn you about two things, you won't be able to close the tailgate and you won't want to drive the suburban anymore.

Assuming you get 20 mpg with the diesel where you get 17 in the burb that is an 18% improvement. 18% of the 250000 miles are free. So that is about 44000 miles that the diesel gods are granting you. At $1.00 per gallon you will be able to purchase your next ruck with the savings.

I hate to do this to you but 18% of the 65k on your burban is 11,700 miles. The true cost of gas is more like $1.50 so you already threw $17,550 down the crapper.

I am sorry to admit that I too drive a gas truck. :whiner: .......for now.

 

[Highbeam]

One more thing, can you tell I'm an engineer?

If you drove 65,000 miles in 16 months than that is about 4000 miles a month. 18% is 720 miles. 720 miles x $1.5 per gallon gets you $1,080 per month down the crapper.

The diesel option can be as much as 5000$ additional on a new truck. 5 months and you're there.

Mileage is one thing, but then there is the power and durability of the diesel. Take one for a test drive.

 

[Tony Eeds]

Highbeam - Thanks for the input!
I would have bought a diesel when I got the Suburban, but there was none available, as they were changing the sheetmetal for the new Isuzu motor.
By the way, my dad was an engineer, so I understand. I became and Architect because I didn't want to learn how to use a slipstick. Then they invented the hand held calculator ..... :confused:
Tony

 

[jeb]

Remember too that they're worth more at trade in time so you don't have to make up for the full price of the upgrade to the diesel in gas savings alone. And diesel is usually cheaper to buy per gallon than gasoline, at least where I live.