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408 Mpg?

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3K views 12 replies 8 participants last post by  rogue1  
J
#1 ·
Ok since there are more and more people building 408 strokers, I figure I'd take a poll and see what kind of MPG everyone is getting for grins :D

Honestly, my dilemma is trying to decide if I should put a modest motor in the Dak for daily driving and throwing a big block in the Gen1 or just sticking with my 408 build. I'm hoping to possibly get at least 12MPG from a blown 408 with a stand-alone fuel management system (Megasquirt). I just can't have two trucks getting horrible MPG lol

Thanks,
-Jason
 
#2 ·
Mine is pretty mild so it might be on the higher end. I average about 14 with mixed driving and have gotten as good as 18 on a couple of tanks while on the Power Tour this year with steady 60-65mph driving.
 
#4 ·
With that being said...

My 408 is pretty new, and most of my driving has been break-in stuff, then burnouts and tests (0-60 stuff, more burnouts, tranny testing, more burnouts, etc.). I've been getting less than 10mpg. Also did I mention that I hit 6500rpm quite often.

Those factors considered- I bet I could get 15mpg on the highway easily. My brother's durango with a 404 get's 17 on the highway, and about 8-10 in town.
 
J
#6 ·
Well, with just this info, I believe I can get about 12MPG with my lighter GenII plus I hear that a blower will actually help MPG but I'm not 100% on that... Would I really be saving a whole lot of Mpg if I went with a 404 or something? That's only 4c.i difference... And before anyone else says it, yes I know I shouldn't be worried about MPG when driving a v8 truck and if I wanted to save gas get a 4banger car blah blah blah lol
 
S
#7 ·
hahaha

408 and mpg in the same thread title! :funny::funny::funny::jester:
 
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C
#8 ·
My carb'd LA motor gets me about 15mpg on the highway doing about 70 to 75mph. But that's a stick shift & a 3.90 rear end.

If you are going to create a 408 combo for your Gen 2 that involves a huge cam or carburetor or anything outside of "mostly stock plus a few cubic inches," then you need to pay attention very closely to the following statement:

1. Do NOT count on that Gen 2 as your daily driver.

That's just the voice of experience talking to you.....
 
C
#11 ·
Let's put it like this... if it's a DD for you, you want to stay away from the cam & carb that I chose. They are almost exclusively top end items. The motor doesn't really come alive until 4500 and it's a pain in the bitch until that RPM. Most of it is the Stage 4 Spec clutch (full metallic with non-sprung center hub). So, while you're driving around town, the power brakes are pretty crappy, the clutch causes the engine to chug & buck & stutter and the manaul steering/spool combo is a pain in almost ALL situations.

Just be sure you don't make too many sacrifices like I did for racing, etc.
 
R
#13 ·
My old boss built his Ram 1500 with a 406 magnum,1.97" Ported R/T Heads,
M1-2bbl, 232/242 544 110LSA Cam with Rhoads Lifters. It actually sounds pretty good and he's actually doing great with MPG. The lifters perform a variation of variable valve timing so only when he gets to 3000-3500 rpm thats when you feel the 236/242 cam kick in other than that the duaration and lift are greatly reduced. Might be something to look in to.
 
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