V8 Conversion MPG Average

[iaintscared1969]

Eitherway you look at it horse power cost $$$$ and mileage shouldn't be a factor. Mace and others have done the cost vs mileage pay off and it equals doing it for the love not the pump. Me I will stay with v-8's just because I like passing people and breaking a new toy. Which brings up a good point...Breakage. Have you considered upgrading the axles if you get all this HP?

 

[jerz4wd]

My FJ40 has 305TPI v8 and gets about 10mpg. Still has stock chip
out of Camaro so I'm trying to get that fixed. Running 700R4, stock 4:10 gears
with 37"s, 1950rpm's doing 65 on gps.

Jerry

 

[JONNYFJ]

Eitherway you look at it horse power cost $$$$ and mileage shouldn't be a factor. Mace and others have done the cost vs mileage pay off and it equals doing it for the love not the pump. Me I will stay with v-8's just because I like passing people and breaking a new toy. Which brings up a good point...Breakage. Have you considered upgrading the axles if you get all this HP?

I have built the toy axles as much as they can be built, I have thought about going to 60s, but I put out about 450hp and 525ftlb of torque and the only thing I have broke is the SM420s tail shaft. I want it to stay a daily driver so I have been thinking about a NV4500. Thing is there will be allot of drive line mods to fit the 5 speed I measured the difference and it was almost 16 inches longer than the SM420. That been said you should know that I don't wheel my 40 so running 37 on the road with Toy 8" should be on problem right I mean I have seen it done.

 

[iaintscared1969]

Nah should be OK. Just making sure you were prepared. So have you decided? Ram,Vortec, or old school? BTW my 350 with a tuneable Holley projection gets 12 if I stay out of it. It still has a 4 speed too!

 

[JONNYFJ]

No I am debating throwing that much into the cruiser I over 20 large in the hole as it is. And with raising gas prices I really need to start looking 4 a DD that gets over 20 MPG I am planning on finishing school when I get back. We will see how much this deployment racks in and then I will go from there.

 

[missipboy]

mine got between 10 and 11 on the highway.
nv4500
4.11's
soa with 35's
crate 285hp gm with a truck avenger carb. it helped having a 28 gallon tank and good speakers.

 

[Texx]

FJ40'S look too much like the box they came in. No aerodynamics. The 2F isn't really struggling, it has plenty of torque, just not much horse power. I got better mileage in my carbed V8 60 (15) than I ever did in one of my V8 carbed 40's. Top off, windhield off, tits in the breeze, no rollbar, nose poking barely above the dash you might get 15. (on stockish tires).

 

[Corbet]

stock 350, Holly Pro injection, Stock 4 speed and t-case, 4.11, 33" = 15mpg
Built 383, Q-jet, Stock 4 speed and t-case, 4.11, 33" = 8mpg

 

[Fast Eddy]

I just talked to moose over at lethal he said No BS on the MPG with a chip and some other little goodies he said it can be done. The CJ was not his first he has also done 2 TJs and a Blazer. Thing is all of them had automatics w/overdrive... Something I don't got

I still call bullshot. With 44s that's almost 1000 lbs just in the tires. No f'n way unless the 'other goodies' include a long downhill between two gas stations.

A '60 is more aerodynamic than a '40.

My guess is that the best mileage would be a 5.3l Vortec with an NV4500 and smallish ilft and A/T tires. I would guess that 15mpg would be possible.

My wife gets 15-20 in her slightly-lowered 2wd suburban with a 5.3.

 

[65swb45]

tlcghost was forced to hold tufftorq's Q-jetted 350,SM420 with 37" MTRs at 55 miles per hour following me up to the 45 run three years ago.

At 55 mph, it got 14.5mph.

somebody's sig line sums it up: aerodynamic....like a brick!

 

[fussy_cruiser]

Q-Jetted 350, SM465, 3.70's and 33 in tires. I get between 10-12 MPG per tank. I think it is actually lower the more hiway driving I do.

 

[JONNYFJ]

This is from TLC4x4

I call Bull****z. Tell your source to clarify/prove it. Do those figures/stats include a Mexican overdrive (coasting downhill with the engine off)??????

WE SELL THE PARTS AND ADAPTERS AS WELL AS FULL TURN KEY INSTALLED CONVERSIONS.
East meets West when we install 2000 General Motors 5.3 Vortec V8 engines in Land Cruisers. Fun for all age Cruisers, this combination mates the no nonsense traditional Land Cruiser design with arguably the best new truck drive trains available to create a reliable, fast and efficient alternative.
Offered with either the NV 4500 5-speed manual, the H55F Toyota 5-speed manual, or the 4L60E 4-speed automatic transmission mated to the Toyota transfercase, the Vortec conversion offers at least double the horsepower with an increase in fuel efficiency as well.
All conversions are compliant with 2000 emissions standards and retain the stock G.M. check engine light and diagnostic system for easy maintenance.
We will convert your Cruiser or one of ours (discounted on Stage 3 restorations) to meet your needs. Conversions are usually completed within 45 days time (with scheduled appointment) and are guaranteed for 12 months or 12,000 miles. We use only top quality components sourced from leaders in the Street Rod and Conversion industries and General Motors to ensure a Quality Conversion Package.

Engine
Vortec 5.3 V8 w/ SFI
255 HP @ 4600 RPM
330 LB-FT @ 2800 RPM
(Standard on all models)

Fuel Economy
Vortec 5.3
City 14
Highway 18

 

[Bret]

383, QFT (Holley 650), 37x13.5 running 65-75 gets a little over 10, more 65 and a little stoplight to stoplight. Soon to get a Q-jet, have to see how it does...

 

[patches84]

I get 21.5 average going from Santa Fe to Boulder in my troopie at 65-70ish MPH with 2000 Vortec 350, H55F, 3.73 axles and 33x1o.50 BFG A/T tyres. Around town I average 14. She can happily go faster, but if I go 85, I can stir up dust with my fuel guage.

Cheers,

Josh

 

[bikersmurf]

69 350v8 w/ quadrajet

Last tank I got 12.3 mpg (US gallon) city and before the last tune up I got apx. 15 mpg on the highway (keeping to 50-55mph) through the hills.

4.11 gears and 33" AT tires.

Electronic converted points distributor w/ mechanical advance curve kit and adjustable vacuum advace (both well tinkered with).

RV cam

For a 39 year old motor with 120,000 miles I can't complain (not rebuilt)

 

[SLOonTheGo]

Engine
Vortec 5.3 V8 w/ SFI
255 HP @ 4600 RPM
330 LB-FT @ 2800 RPM
(Standard on all models)

Fuel Economy
Vortec 5.3
City 14
Highway 18

I find that kind of odd. I have a 2001 Silverado step side with the same engine. I have a k&n 2nd gen intake system and flows to give better breathing and when I keep off the gas at highway speed I get around 20 mpg. In town around 15 or 16.

My 40 with the same engine I just can't see getting nearly the same mileage. Shes heavier and shaped like a brick. You don't drive it, its more like guiding a brick in a hurricane.

just my .02

 

[madoc1]

i get about 10 with a 355-edelbrok2101-edelbrock650(carter knock off i think) 4.11s and 30 inch tires.

djangle, i have aset of 3.70s just waiting go in, and would like to put on a set of 33's. i see you have this combo- are you happy with it?

fuel economy is not the largest issue, but like to cruise at 60 at lower rpms. jim

 

[HogDriver]

I swapped my old carbed 350 for a Vortec 5.7 from a 1500 Silverado. Did my own wiring harness. Keep in mind I have a 4 speed (SM465) and i do wish i had a 5th gear which would help my MPH since it is sometimes a daily driver as well as my wheeler. I don't drive over 65mph and I get ~15mpg.

If you want MPG, I suggest a KIA.