914turboford

I'm putting together the parts for a 2WD CJ5 hot rod thingy. I am planning on using a 2002 Tahoe 4.8. I am hoping that I might get as good of mileage with the 4.8 as I would if I use an LS1 with the same tranny. What do you think? The 4.8 runs on regular so I assume it has lower compression but since it is smaller maybe that will make up for it? The epa mpg rating for a C1500 is only 19 highway and an LS1 camaro rating is like 25, but I've heard they can get close to 30. I wonder if an F body with a 4.8 would do that? (Not that anybody would)

unknown pontiac

Its not a dd man. Get a 6.0 they cost the same as a 4.8. If you care about ur mpg get u a honda dude. You Can buy one for a G. Good Luck on ur (thingy)

KENS_SS_4

Fuel economy is not apples and oranges. It is based off the engine, gearing, weight and wind drag.
Would you expect to get 100 miles to the gallon if you used a moped drive train?

thunderstruck507

iTrader: (18)

it would probably do worse than the ls1

my v6 in my 92 chevy truck gets worse mileage than my cammed stalled ls1, the poor thing can barely move itself...

blk/slvr02ss

iTrader: (21)

My 2001 GMC shortbed/stepside w/a 4.8 gets 20mpg in the city and the truck is 4100lbs so i would say in a 3600lb car it would get better.

rjwz28

That's common with the 4.3 V-6. I think the extra torque of the 4.8 helps things out a little in that department, although I still would prefer a 5.3 or 6.0.

Element

iTrader: (5)

I doubt a 4.8L f-body would get as good gas mileage as a stock LS1 car. There's the line between not having enough power and getting lower gas mileage because the engine is constantly struggling to move the vehicle (I had a 18' moving truck with a tandem-axle trailer hauling my T/A when I moved that had the 4.8L...talk about an underpowered, dangerous brick) and an overpowered engine that gets poor gas mileage. The LS1 cars seem to be right on the line of having an engine that makes enough power to move the car with plenty of headroom, but aren't so hot from the factory that gas mileage suffers from making power.

rjwz28

The lighter weight of the LS1 over the 4.8 doesn't hurt either. I am not a fan of the 4.8, but if they insist on keeping the 4.8 on the engine list, I firmly believe that it needs to be the base engine. The 4.3 V-6 is long overdue for burial. Put an LQ4 in that "thingy" and go play!

blk/slvr02ss

iTrader: (21)

My Truck being as small as it is fine w/a 4.8 and i think the new ones have over 300hp now which is not bad.W/155,000 miles on her and she still gets great gas mileage and moves pretty good when u need her too.

Starz T/A 17

iTrader: (6)

That really doesn't make sense considering that the v6 F-bodies with a 3.8 dont have a problem moving the car and getting decent MPG's
THIS!!! you cant compare the MPG's of a LS1 F-body to the 4.8L in a truck. Gearing, transmission, weight, and drag, in addition to other variables are all going to have a big effect on fuel millage. The overall setup will probable have a bigger effect on MPG's then the engine swap.
In all reality If you do the swap I would not expect great MPG's over a stock LS1, because LS1's in a F-body and the 3800 series V6 in a F-body are pretty close as far as MPG's go, so I would expect the same from a 4.8

justin455

Yup. Too many variables. My stepdad has a 99 Dodge Ram Van with the 3.9 V6. It has to try so hard to move it's own *** it's get 2-3 MPG worse than a 5.2 V8 equipped one does.

If you really wanna maximize mpgs then you need to remove as much weight as possible and switch to the 2.7X gears A4's can have.

Pro52R

iTrader: (15)

I know alot of 5.3 truck guys who get better fuel mileage than the 4.8's get

Gordon0652

iTrader: (4)

I get 18mpg in my truck with the 4.8 at 74mph in third gear! Though i was in Drive, two hours in third. haha

sway99bird

iTrader: (22)

There is a mod on here with a 4.8 in one of his TA's I think his name is y2k ta ask him......

But I think he is building it for the track only tho....