Well I just drow from LA to Mammoth, well actually June lake but who cares. A few weeks ago i did the deck plate and ISR mods, the altitude was pissing me off. Well anyway up in the mtns i can actually get out of my own way now but the MPG gain was much more then i was expecting. I just drove 270.6 miles to bishop on 11.9gal which equals out to 22.7mpg. This was according to my odo and i have stock tires. Oh yea, i was going 75-80 the entire way.

While i was driving down in LA i drove in a way i should have goten ~16mpg cuz i was liking the power down at sea level but instead of 16ish i got 18.2

To put this in comparison. Before i did these mods i did that same 270mile trip to bishop towing my old 90' waverunner (trailer plus ski is less then 500-600lbs) and i was going 60-65 the whole way. I got 20.1

Needless to say im very impressed. Just thought i would share.

 

All hail absurdly flawed testing methods as proof that mods which according to all laws of physics and thermodynamics should not make one bit of a difference, in fact do make no less than a huge improvement

 

I am with ya twichee...the deckplate and ISR mods do help, mainly with power and response...but I dont think you are seeing those kinds of gains in mpg...the two tests stated are definately not the same conditions and load...

 

Part of the increase in MPG is the higher altitude. You WILL get better MPH up there then down here no matter what you do, this is due to lower drag due to lower air density.

I explained it better in one of your other threads i think.

But still, good numbers, and the deckplate and ISR will help with throttle response and adds about ~10hp - 13hp. As for MPG, it won't effect too much, it does allow the engine to breath easier and thus gives you a little boost id MPG but it all depends on how you drive it.

If you drive it the same as before the mods then you will see an increase, but if you have to always use that extra power then you will see a decrease.

 

it makes no sense that it works, but it does haha. The thing that really got me was i was driving alot harder then normal while i was down at sea level. still got 18. thats was really got me. But i also had very similar millage going from june to the sac delta 23 there and 21 back. So i dont know. It was all up hill coming back too. Once i move back down to sea level we will really see if things change. who knows

Best part about this whole thing. Cost all of $13

 

THe other thing was is interesting, I compaired my mom 03 v8 avgs ~20 on the hwy. On the same drive with similar speeds, i only got 16. It is uphill basically the entire way. and all under 4,000 feet.

 

exactly what I was thinking!

 

i put my cap back on the deckplate due to power and mpg loss, waste of time imo

 

I just did mine last night, it works great, sounds great!

Definatly has more power to it now, better response on the trottle