What mileage to expect - The 1947 - Present Chevrolet & GMC Truck Message Board Network

gerry giordano · 09-07-2003, 02:00 PM

Can't use the search for now so I'll ask what's probably been asked many times before: What kind of milage can I expect from a 350 in one of these that's set up pretty much stock? Is there a great difference between those with automatic and those with a stick? Seems like automatics are the more commonly found too.

Thank you.

68 Suburban · 09-07-2003, 02:17 PM

A lot will depend on what rear end you are running and what type of driving you will be doing.

**StingRay** · 09-07-2003, 02:26 PM

I have a 350 with stock compression, a mild cam, 194 heads, q-jet, K&N air cleaner, MSD 6a, curved dist with adj vac adv, performer intake, Z28 oil pan with windage tray (worth a few HP and wee bit of fuel economy), Clutch fan, rams horns with 2" duals running turbo mufflers and I have a turbo 350 with a 3.73 rear end. I get about 12.5 MPG (US gallons) at 70 MPH. I also get the same at 65 towing an unloaded 2500 lb flat deck and about 10 hauling the same trailer loaded with half a truck. Not sure what I'd get at 60 but it would probably be about 13 or 14 MPG. A 3.08 would really help on unloaded cruising as would a 700 R4. Hope this helps.

71-longbed · 09-07-2003, 02:35 PM

see below for my details...i'm pretty sure i have 3.08's in the rear ..the best i've gotten on the highway is 16mpg .... around town probaly 10 or 11 .... all depends on how planted your foot is

*Phillip Johnson* · 09-07-2003, 02:44 PM

Ive had several of these trucks. the best I ever got was 16mpg stock, 350 350/turbo with a quadrajet.
I have a 71 with 350/350 turbo with a quadrajet and all Im getting now is about 12 mpg. I have yet to do anything under the hood except check the oil. I think I can pull a good 15 out of this truck with a set of plugs and bump up the timming.. Just my 3.7 cents worth

OneMpg · 09-07-2003, 03:10 PM

I do mostly around town driving and I'm getting between 8 and 10. I dunno if this helps you at all because my 350 isn't stock. All the performer crap, Doug Thorley's, etc. I have a 4spd, but I think the reason my mileage is so bad is because my rear end is geared too high. I'm not sure what's in there, I will have to pull the cover when I get a chance but I definitely need lower gears. Hill starts can be real tough in second. I've actually been using my granny on hill starts. I want posi too so I may just swap in a Dana 60 with a detroit. I haven't really had a chance to calculate freeway mileage since I got it dialed in but I'd guess it's pretty descent because I run real low RPM's at speed. I think it's about 2500 at 65 or so.

-Dave-

Huck · 09-07-2003, 08:18 PM

16mpg around town---20-22mpg highway.
350 crate with:
Edelbrock Carb and intake
HEI
Headers
307posi
5 speed out of a 96 Silverado
If I keep my truck and drive it 20,000 miles per year, in 2007 the 5 speed will have paid for it's self!!

nroden · 09-07-2003, 10:11 PM

I have a 72 with a all stock 350 and TH350. Original rearend also. Orig. QuadraJet, replaced the timing chain, ignition, plugs, ect. all with stock. Nothing major ever done to it. I get about 12-13 MPG. I am wanting to do electronic ignition though and maybe get the carb rebuilt and tuned up or get a new Edelbrock. Toneau covers also can help!!!

09-07-2003, 02:00 PM	#1
gerry giordano Registered User Join Date: Sep 2003 Location: Arizona Posts: 44	What mileage to expect Can't use the search for now so I'll ask what's probably been asked many times before: What kind of milage can I expect from a 350 in one of these that's set up pretty much stock? Is there a great difference between those with automatic and those with a stick? Seems like automatics are the more commonly found too. Thank you.

09-07-2003, 02:17 PM	#2
68 Suburban Registered User Join Date: Oct 2000 Location: From Chicago, Live in Phoenix, AZ Posts: 6,802	A lot will depend on what rear end you are running and what type of driving you will be doing. __________________ Just sitting here contemplating contemplation.

09-07-2003, 02:26 PM	#3
StingRay Senior Member Join Date: Mar 2000 Location: Saskatoon,SK,Canada Posts: 2,476	I have a 350 with stock compression, a mild cam, 194 heads, q-jet, K&N air cleaner, MSD 6a, curved dist with adj vac adv, performer intake, Z28 oil pan with windage tray (worth a few HP and wee bit of fuel economy), Clutch fan, rams horns with 2" duals running turbo mufflers and I have a turbo 350 with a 3.73 rear end. I get about 12.5 MPG (US gallons) at 70 MPH. I also get the same at 65 towing an unloaded 2500 lb flat deck and about 10 hauling the same trailer loaded with half a truck. Not sure what I'd get at 60 but it would probably be about 13 or 14 MPG. A 3.08 would really help on unloaded cruising as would a 700 R4. Hope this helps. __________________ Saskatoon, Saskatchewan Canada

09-07-2003, 02:35 PM	#4
71-longbed Its Magically Delicious Join Date: Jan 2003 Location: oregon Posts: 2,398	see below for my details...i'm pretty sure i have 3.08's in the rear ..the best i've gotten on the highway is 16mpg .... around town probaly 10 or 11 .... all depends on how planted your foot is __________________ 71 C10 LWB 350sbc -TH350 12 bolt 3.42 Posi Of all my favorite things to do, The utmost is to have a brew. My love grows for my foamy friend, with each thirst-quenching elbow bend. Beer so frosty, smooth, and cold it's paradise pure liquid gold. Yes beer means many things to me that's all for now cus I gotta pee.

09-07-2003, 10:11 PM	#8
nroden Registered User Join Date: Jun 2001 Location: Springfield, MO Posts: 1,098	I have a 72 with a all stock 350 and TH350. Original rearend also. Orig. QuadraJet, replaced the timing chain, ignition, plugs, ect. all with stock. Nothing major ever done to it. I get about 12-13 MPG. I am wanting to do electronic ignition though and maybe get the carb rebuilt and tuned up or get a new Edelbrock. Toneau covers also can help!!! __________________ Nick Rodenberg 72 Cheyenne 10 V8 350/TH350 white/ochre/white/ochre, ochre/saddle interior Retired and in the dry... still runs. I now drive Red '01 Ford Focus... better MPG!!!

09-07-2003, 02:44 PM	#5
Phillip Johnson Account Suspended Join Date: Apr 2000 Location: Grants Pass, Oregon Posts: 1,580	Ive had several of these trucks. the best I ever got was 16mpg stock, 350 350/turbo with a quadrajet. I have a 71 with 350/350 turbo with a quadrajet and all Im getting now is about 12 mpg. I have yet to do anything under the hood except check the oil. I think I can pull a good 15 out of this truck with a set of plugs and bump up the timming.. Just my 3.7 cents worth

09-07-2003, 03:10 PM	#6
OneMpg Registered User Join Date: Jul 2003 Location: Pleasant Hill, Cali Posts: 43	I do mostly around town driving and I'm getting between 8 and 10. I dunno if this helps you at all because my 350 isn't stock. All the performer crap, Doug Thorley's, etc. I have a 4spd, but I think the reason my mileage is so bad is because my rear end is geared too high. I'm not sure what's in there, I will have to pull the cover when I get a chance but I definitely need lower gears. Hill starts can be real tough in second. I've actually been using my granny on hill starts. I want posi too so I may just swap in a Dana 60 with a detroit. I haven't really had a chance to calculate freeway mileage since I got it dialed in but I'd guess it's pretty descent because I run real low RPM's at speed. I think it's about 2500 at 65 or so. -Dave-

09-07-2003, 08:18 PM	#7
Huck Senior Member Join Date: Jun 2001 Location: Shelbyville, KY Posts: 3,269	16mpg around town---20-22mpg highway. 350 crate with: Edelbrock Carb and intake HEI Headers 307posi 5 speed out of a 96 Silverado If I keep my truck and drive it 20,000 miles per year, in 2007 the 5 speed will have paid for it's self!!



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