Whiskeyboy84

iTrader: (8)

Hey guys like it says I would like to know what kind of fuel mileage you guys are getting so if you can Post up your combination to include Engine, Mods, Transmission, Stall, Rear gear ratio, and Tire height. I am just looking for real world averages and want to compare setups I am currently doing a Lq4 swap into my 1973 El Camino and have sold off my 200-4r and have been thinking of doing a Tremec t-56 magnum swap with the .50 6th and want to see what kinda of fuel mileage guys are getting especially out of similar weight cars and setups would like to compare stock to wild setups as for now it is a stock lq4 but a blower, cam, and head work are in the future. I already have long tubes 1 3/4 primaries for it I have 3.73's with 25.6 in tall rear tires I am rocking 17x11's with 315/35R17's. I drive 80 miles per day for work and I want to be able to daily drive my El Camino once it is done. Thanks Guys!

Stu Cool

iTrader: (13)

My car weighs about 3600 with me in it. You can see the mods, or lack of them in my sig. Consistent highway mileage at 70 mph/2250 rpm with AC and cruise control on is 24-26 mpg. My rear tires are 28" tall. I have seen close to 30 at 65 without the AC.

Whiskeyboy84

iTrader: (8)

Hey Stu thanks for posting we have had a bunch of viewers but not many people want to reveal there fuel mileage I guess LOL.

garys 68

iTrader: (1)

I might be one of the few here that considered practicality and mileage. I designed my build as a daily driver.
5.3 in a 72 Olds, T10, 2.73 rear, around 22mpg combined.
My 68 vette with a 6.0 LQ9, Richmond 6 speed, 3.08 rear has seen 26mpg hiway.
Message...get your rpms as low as possible if mpg is your concern. These motors pull from 1500rpm.

Whiskeyboy84

iTrader: (8)

Gary, I couldnt agree more with get the revs as low as possible and fuel mileage will increase to a point but at that magic point if you go beyond that you will actually begin to see a decline in fuel mileage as it then becomes to hard for the engine to maintain its speed without Lugging the motor down its like trying to put a your trans in overdrive and cruise a 50 mph without down shifting to a lower gear you will see you would be flooring the gas pedal and not really going anywhere much like the Honda Civics next to you at a stop light LOL. I know my old Carb'ed SBC the sweet spot for max fuel economy was actaully right around 2000 rpm I had ran it with 3.42's 26.5 inch tall tires and a turbo 350 for years getting right around 10mpg then I put the 200-4r in it and got 15-16 it wasnt until I put the 3.73's in it that I saw 17mpg on the highway out of the car. So my thoughts are if i can get 20-25 mpg running a 200-4r in my car and it only cost me 3000 grand to do so, and compare that to other guys who may be running the t56 aand if the fuel mileage gains are maybe 1-2 is the extra couple thousand dollars really worth the added fuel mileage. I know most people on here are die hard big number Hp guys Fuel mileage be damn'ed but with gas prices continuing to rise I want to be able to afford to drive my car and not stare at it in the garage or on the back of a trailer.

chuckd71

iTrader: (23)

Mid 20s is pretty common. I doubt people want to type out their entire setup since there wouldn't be much point in doing so. There are tens or hundreds of thousands of combinations and no way to really attribute a real mpg value to any of them, an exception maybe being transmission. A t56 would be .17 "more" overdrive, so you'd be turning that many fewer rpms. It's unlikely a t56 swap would ever pay for itself. The 200 already has a better final gear than a 4l60/80/etc.

Whiskeyboy84

iTrader: (8)

Chuck, Thanks for your reply I have sat down and done the math using a difference of 5mpg and a difference between a built 200-4r and a t56 swap being 2500 dollars roughly with my commute being 80 miles per day round trip if I could obtain a 5 mpg increase I would recoupe the difference in the transmission set ups in just over 4 months. I understand the fact that there are som many different combinations but I think if we could compile a Thread with good useful information we could assist people with future builds just as there are proven 500RWHP setups we could have proven 20-30 mpg setups also few people realize it but the more effiecent you make HP the more HP you make.

DW SD

6.2 liter stock L92 with 6L80 in 51 ford pickup. 3.5 rear end with 275/35/18 tire. I've seen 14 to 16 combined driving. My truck weighs about 3200 lbs.

vannatta20

iTrader: (4)

24 mpg on the hwy in a 68 firebird with a 6.0 and t56. the t56 is key in getting better mileage

Whiskeyboy84

iTrader: (8)

Thanks for your Replies guys Keep them Coming. If we can get enough maybe the moderators will make it a sticky so it is easy to find for anyone who maybe interested.

LS1 pwrd NOVA

iTrader: (2)

Heres what I got in my bone stock 99 trans am ws6. ls1 4l60e with 85k miles
It's not a swap, but real world numbers if someone uses this engine tranny combo.
Car has 26" tall tires allaround that are wide 275/45/17 & 3.23 rear gears.
I get around 15 city and 23 highway going 72 mph all hand calculated.
I don't think it can really get too much better all around stock.
For a daily, Adding a t56, less weight, a good lean tune running 87 could work.

goodwrenchbutch

1989 Trans am GTA 6.0/4l60e. small comp cam(530 lift), 3600 yank stall, 3.73 and 245-55-16 that has not been dyno tuned. I average 20 mpgs driving two lanes to work, 24mpgs on the interstate. it doesn't matter if I run 65 or 80 on the interstate, at 80 mph my cars is running 2800 rpm. These engines like to breathe. My friend had a 98 z28 bone stock and we switched out the 2.73 to a 3.73, calibrated the speedo and test drove. he gained 8 mpg on the interstate and it was a ton funner to drive. Another friend has a 56 Bel Air with a stock 5.3/4l60 3.70 rear and he gets 24 mpg on the interstate.
You have to remember that you are not starting with a light or aerodynamic car like a Corvette

5.0 LsX

iTrader: (7)

when I had a stock 02' ls1 w/ cold air intake & longtubes, t56, 3:73's in a 3100lb mustang I got 28mpg freeway

N20zuki

I see 15-18 in town, its hard to drive normal. 26 Hwy is the best I have gotten out of it. Stock 5.3 with headers and a MP112 blower backed by a T56.

i r teh noobz

iTrader: (4)

88 Nissan 300ZX
2002 LM7, PRC heads, 224/228 112 TSP cam, LS6 intake
Self tuned (no dyno)
TKO600 w/.81 OD
3.7 rear
225/50/16 tires
~3200 lbs.

I average about 16/17 around town, turned 22/23 on a long trip recently. Turns over 3k RPM at 70 so a better overdrive gear would help alot.

redtan

iTrader: (5)

In a 3700lb car with a 6.0 and T56 you can get high 20s on the highway easily. More so if you have a well built top end with some decent compression.

I would look into LQ9s with 243s for more compression than LQ4s.

Whiskeyboy84

iTrader: (8)

Great info guys thank you for all your responses I like the fact that we are getting so many different combos.

fieroguru

iTrader: (1)

All the info is in my signature except tire diameter of about 25" (245/50/16) and 3.55 final drive with a 0.62 6th gear.

casias

iTrader: (1)

Drivetrain: LY6/6l90 stock
Vehicle: 1999 Dodge Dakota R/T
Ring and pinion ratio: 3.92
Tires: 255/50-17, 27 inch diameter
Mileage: 18 mpg in mixed city/hwy driving

The engine RPM is about 2300 at 65 mph. If I swapped to 3.55 rear gears, that would be lower, and the MPG may improve, slightly. At least it would cruise a little quieter.

llorracs93s10

iTrader: (5)

Not what I wanted to read, lol. I have a l92 with a cam long tubes 3 inch exhaust with 4.10s through a 4l80e and 28.3 inch tires and was hoping for decent mileage, lol.