![]() |
Register or Log In To remove these advertisements. |
|
|
![]() |
|
Thread Tools | Display Modes |
|
![]() |
#1 |
Registered User
Join Date: Oct 2011
Location: NorthWest
Posts: 131
|
How to optimize a RCSB for gas mileage
In the market for a 99-07 chevy/gmc single cab short bed (rcsb) 2wd..... I'm looking for one with a 5.3l .... I've always wanted one. It will be a commuter vehicle for me. Driving 55-70 mph about 80-90 miles a day for 3 or 4 days a week.
My question is, what kind of gas mileage can I expect? I would ideally like to push it to 22 mpg. I know this is a bit of a stretch. What speed, air dams, tonneau cover, etc... can I add to achieve this? Will a 4/6 drop help at all? I plan to add a 4/6 drop either way. What wheel/tire size will work best? Will a 4.3 or 4.8 be any better? My thought process is that a bigger motor wont have to work as hard. Any thoughts or suggestions are appreciated. I know this is not the best "commuter" vehicle but I'm currently driving a v6 tacoma 4x4 getting 16-18 mpg. |
![]() |
![]() |
![]() |
#2 |
driving is in my blood
Join Date: Dec 1999
Location: Mesa AZ
Posts: 5,723
|
Re: How to optimize a RCSB for gas mileage
Doesn't matter if it isn't working as hard, your still turning a certain number of RPM's and moving air threw the engine that needs fuel added. The 4.8 vs 5.3 seems to work out like your thinking, but the v6 will get better mileage.
As for mods to help, everything you listed helps. Bed cover, lower the truck, keep small rims on it [the lighter weight the better]. Make sure the factory air dam under the front bumper is there.
__________________
-78 c10 short/step: 388cid, M20, 5/5 drop, lots more. Playtoy and first vehicle. -98 c1500 x-cab: 5.7L, 17" rims, 5/6 drop, flowmaster, helper bags,NBS rear disk brakes. -02 Suburban 4x4: leveled front -CBR600F4i, CBR600RR, CBR1000RR, and standup skis DISCLAIMER: I cant spell for the life of me. |
![]() |
![]() |
![]() |
#3 |
Registered User
![]() Join Date: Jul 2006
Location: Ozark, MO
Posts: 4,887
|
Re: How to optimize a RCSB for gas mileage
4.3L/5 speed manual is your huckleberry if you can find one. It has plenty of power and is efficient in the right package. Custom tune, smaller/lighter wheels and low rolling resistance tires. Synthetic fluids throughout. You could expect about 18mpg combined, 19 tops if you drive like an old lady. 22 combined is probably not going to happen.
__________________
'20 Silverado Trail Boss ~ '17 Tahoe ~ '79 K15 Sierra Grande ~ '76 Blazer 2wd ~ '71 Cheyenne swb ~ '55 Pontiac Safari ~'50 3100 bagged ~ '80 Wife ~ Late model kids
|
![]() |
![]() |
![]() |
#4 |
Registered User
Join Date: Oct 2009
Location: Buhl, Idaho
Posts: 1,438
|
Re: How to optimize a RCSB for gas mileage
My 06 rcsb had the 4.3/Auto and when it had the 17" steel wheels it got 17mpg. The truck was lowered 5/7 K&N cold air intake and magnaflow cat back exhaust. I would get the 5.3 like you mentioned.
Here is a picture: ![]()
__________________
86 c30 crew cab dually 454/400 4/6 drop SOLD 1-8-11 1981 chevy K10 short Bed Scottsdale SOLD 10-26-2020 67 GMC Stepside Straight six/3 on the tree "The Peach" 2020 Silverado Double Cab LT Z71 5.3 8 speed Daily Driver K10 build http://67-72chevytrucks.com/vboard/s...d.php?t=671934 The Peach build http://67-72chevytrucks.com/vboard/s...d.php?t=733903 ![]() Last edited by Matt Man; 03-18-2020 at 09:31 PM. |
![]() |
![]() |
![]() |
#5 |
Registered User
Join Date: Oct 2011
Location: NorthWest
Posts: 131
|
Re: How to optimize a RCSB for gas mileage
Would going to 3.08 gears help much?
The new ecotec motors with the 6l80e transmissions really perform well both power and economy wise. Seems as if 3.08s would act similar |
![]() |
![]() |
![]() |
#6 |
State of Confusion!
![]() ![]() Join Date: Jul 2002
Location: Gulfport, MS USA
Posts: 46,860
|
Re: How to optimize a RCSB for gas mileage
I have owned several 4.3V6 and a 4.8 V8 ones. With today's ethenal gas, seeing 20 is possible, but a little tuff. I loved them as DDs. For best gas mileage, keep the skinny factory wheels and tires. I had 8" wheels and 265/70 tires. I liked the ride and handling, but it will eat a bit into the MPG. AS mentioned a 4.3 V6 and manual will give you the bext chance of MPG. Most trucks came with a 3:42 rear gear with the V^ till aroun 2005, then they went to 3.23 gears. As far as automatics, my 4.8 V* one ended up with the best MPG average consistently.
My 92 V6 w 5 speed average 21 MPG Hwy (for whatever reason in Colorado Springs/Denver I averaged 23-24) 2002 V6, 3.42 gears 20 MPG Hwy 2007 4.8 V8, 3.23 gears 21-22MPG 2006 V6 3.23 gears 21 MPG Now Highway for me is 70-80, mostly flat land. I miss my RCSB truck. Love them as a daily, and they are getting harder and harder to find.
__________________
Bill 1970 Chevy Custom/10 LWB Fleetside 2010 Toyota Tacoma PreRunner SR5 Double Cab - DD Member of Louisiana Classic Truck Club (LCTC) Bill's Gallery Life isn't tied with a bow, but it's still a gift. Live simply. Love generously. Care deeply. Speak kindly. Leave the rest to God! |
![]() |
![]() |
![]() |
#7 |
Registered User
Join Date: Oct 2011
Location: NorthWest
Posts: 131
|
Re: How to optimize a RCSB for gas mileage
Thanks for the info from your personal experience!
I'm pretty dead set on a 5.3L. I know they are getting tougher to find, hence why I'm still looking. With that said, I'd like to optimize one with the 5.3. I know getting a 5.3 is counter intuitive when it comes to wanting good gas mileage but we have owned several vehicles with the 5.3 and can't imagine going with another motor. Plus they typically come with nicer interiors than the standard 4.3L work truck. The desire for decent fuel economy is a shorter term desire as I travel often right now. In years to come a cammed 5.3 or 6.0 might be in store for this project. |
![]() |
![]() |
![]() |
#8 |
Registered User
Join Date: Dec 2012
Location: Temple City
Posts: 3,587
|
Re: How to optimize a RCSB for gas mileage
If you really want mpg. Take a look at the 14+ Silverados with the V6.
I have a 18 crew cab with a 2/4 drop, and usually average right around 26 highway at 66-70 mph. Goes slower doesn't help, and faster it drops quick. Trailing a semi helps alot, but I rarely get to cruise behind one. If I cruise from LA to Lancater, and back. Ac on or off doesn't matter much. Even with the hill going there I get right around 25 round trip. I have hauled a 7500 trailer over the mountains around lake tahoe, and it did amazing. As for the early model your looking at. I liked my 4.8 in the new 07 model. 21-22 highway at 70-75. It had 3.23's when I got it, and I swapped to 4.33's. The hwy mpg stayed the same, but the city mpg went up alot. It used to get something like 13/22, and after the gear swap it got like 17/22. Tonneo covers help alot of you have a tool box or keep stuff in the bed. As this messes up air flow. So if you keep the bed clean they do effectively nothing. Also consider a roll up soft tonneau as they as very flexible since it they roll up. When I got my 07 I put in a tool box and my mpg went from 21 to 17 hwy. I got a tool box soft tonneau, and it went back to 22. Not enough to justify it by itself. |
![]() |
![]() |
![]() |
#9 | |
Registered User
Join Date: Oct 2011
Location: NorthWest
Posts: 131
|
Re: How to optimize a RCSB for gas mileage
Quote:
I wish a 5.3/6l80e combo was in budget. Especially those new ecotec 5.3s... but that is beyond my budget for a daily! |
|
![]() |
![]() |
![]() |
#10 |
Registered User
Join Date: Aug 2015
Location: Starbase 4
Posts: 118
|
Re: How to optimize a RCSB for gas mileage
Had the RCSB 4.3 5speed for 7 years.
245-70 tires on the steel wheels, 3.23 rear. 15-16 mpg in town and about 21 highway. (a mile or two less in the winter with the crappy winter gas) Unless I drove like an idiot....
__________________
2006 Sierra RCSB V6 5 Speed RWD. |
![]() |
![]() |
![]() |
#11 |
Registered User
Join Date: Sep 2011
Location: Ark City, Kansas
Posts: 3,332
|
Re: How to optimize a RCSB for gas mileage
I bought my buddies 2005 1/2 ton SWB, looks exactly like post 4
He was looking to tow with it. It has the tow package 5.3 automatic trans,3.73 gears. THe tow package rides a little stiff, doesn't bother me. He blessed me by selling it to me shortly before he pass, so I will own it, till the cows come home. It gets 20 MPG, I've heard of the standard suspension pickups that have the 3.23 gear get 22-24 MPG, with the 5.3 He had a 2000 model standard pickup, 2WD, SWB with the V6, it got 20 MPG. THe v6 wasn't gutless, but man, the 5.3 has great power. I wouldn't buy anything but a 5.3 |
![]() |
![]() |
![]() |
#12 |
Registered User
Join Date: Dec 2010
Location: livingston co.mi
Posts: 2,457
|
Re: How to optimize a RCSB for gas mileage
I picked up mine a little over a year ago a 01 5.3 has 183K+ miles I got a little over 19 MPG @ close to 80MPH (with the JD in the back 200 of the 400 miles)
Since then I had a misfire code so I replaced all the coil packs It seemed to pick up some MPG but I have not checked it yet And yes it is a fun little daily driver it was worth the wait
__________________
California 65 GTO---Texas 64 burb 283 ---Oklahoma 67 CST SWB BBW wood bed 327 2004r---New Mexico 72 k10 350 350 auto---Georga 72 short step project |
![]() |
![]() |
![]() |
Bookmarks |
|
|