HO or explorer or 351 fuel economy?

[BerniniCaCO3]

So I've got the 5.0 lopo in my car right now.
I get low 20s mpg highway, and just 13, 14 city.

However, I recently learned from a coworker that his mercury moutaineer only got 12mpg HIGHWAY!

So here's my question:
is the 150hp 5.0L "lopo" merely cheaply built, and if so, can I bump that to 200, 250 horsepower and still get the same horsepower? "free" power? (albeit at a cost of $500, $1000 in parts and a solid weekend to swap out the engines).

Or if I put in the explorer engine, will I, too, see just 12mpg highway?

If so, really, I don't mind 150hp if it means 22, 24mpg highway versus halving that to just 12 for the extra 100 hp. I'm not racing my 20 year old station wagon.
But if I can get a lot of extra power just with better made parts, and not hurt fuel economy TOO much....

[johnunit]

You'll get the same or better economy with explorer or HO parts, generally speaking.

He's losing a lot of mileage because:
1) he has even worse aerodynamics
2) Mounaineers have full-time AWD, meaning he's fighting the friction and weight of an entire second differential, a transfercase, etc.

[1980c10]

I got 20mpg highway with the lopo, and went to 24mpg after the H.O. and mass air swap

[BerniniCaCO3]

Alright: it's agreed then. I need to do an HO swap (I've sort of been tossing around the question for months now).

How much would it cost me do you think? How much time should I budget? (just what am I getting into!).

[mrltd]

The explorers are AWD and a little heavier than the panthers....and not very aerodynamic....the exhaust is horrid. The same motor in the cobras had 30 more HP...

(pretty much what Johnunit said)


I got the same milage with an HO swap. My explorer swap is not stock (cam injectors etc), and it gets 16-19mpg.

[1987cp]

It's not what a cheapskate like myself think of as a budget build, but David Clafin at sbftech claims something like 26mpg while delivering over 360rwhp. I'm therefore sick of getting half the mileage while delivering a lot less power. I'd suggest having a look; his threads are worth reading.

[merc91]

i just went from 17mpg with my LOPO to a ported intake/gt40P/HO cam/1.7RR's, mass air... that gets me 17MPG with 300hp or so. Doubled the hp and kept the same milage, not a bad deal.

[Pirate]

It's not what a cheapskate like myself think of as a budget build, but David Clafin at sbftech claims something like 26mpg while delivering over 360rwhp. I'm therefore sick of getting half the mileage while delivering a lot less power. I'd suggest having a look; his threads are worth reading.

I can't stand going over there, sorry.

[grandpaslincoln]

I'm getting 21 MPG with a 4bbl and Duraspark II on a 302 CFI motor.

[pantera77]

All my boxes get between 17-22mpg depending on what mood their in.

[86VickyLX]

My car varies between 17-21mpg. I think it'll be better when I convert it to mass air.
Explorer 5.0 bored .020" over, gt40p heads, mark VII computer, lincoln log manifolds, stock dual exhaust, stock trans, and 2.73 rear.

[sly]

two full tanks after swapping in the new computer and ignition module and I'm spot on 17.7 mpg on 90% city driving (typically around 40mph). Now I wanna take it out on the highway and find out what it'll really do. This is with the stock lopo, performance air filter, dual exhaust, aod-w.

[85crownHPP]

17 city is marvelous!

[91waggin]

I'm lucky if I see 9 city. But I have a very heavy foot.