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Discussion Starter · #1 ·
I presently own an 08 Duramax diesel with 550hp at the wheels. it is a crew cab that runs in the very low 13s:D. it get 21-24 mpg ( canadian mpg) at highway speeds. i am thinking of getiing out of diesels and getting a supercharged double cab tundra. how is the fuel milege on the truck? How r these truck in the cold canadian climate.Thanks Kevin
 

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My interstate mileage didn't change at all after getting the supercharger. Still ~17. In town I can average 13.5 over an entire tank if I drive gently, but what fun is that?
 

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1 us gallon = 0.833 canadian gallon, from what I understand.

If you do the conversion, it seems that you get 17.49 - 19.99 mpg (us). That seems to be somewhat higher than the average mpg reported by various members of the forum. Your gas mileage depends a lot on your driving style. It seems like you drove very conscientiously in order to get that sort of gas mileage on your duramax. I would suspect that if you are such a driver, you may get somewhat similar gas mileage on a tundra.
 

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If gas mileage is your concern, stay with your diesel. When I originally switch from the duramax to my tundra, I was excited that I was getting similar 17-18mpg to the duramax. Now I get 15-16mpg on the tundra. The duramax got 17-18 consistently almost regardless of driving style. Not so with the tundra.

Oh yeah...I am not supercharged...wouldn't think it would get better with a SC'r.
 

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Discussion Starter · #6 ·
i mostly want to know if there was a drop in fuel mileage after it was supercharged, and if so, by how much?
 

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My MPG went up a good bit after the SC.
I did a MPG test, driving both ways from Portland to Salem (Oregon) maintaining 70mph and was able to pull 20.9 going and 21 coming home.

-AC was on
-using premium fuel from PacPride (cardlock)
-reset MPG once vehicle was up to speed

Was getting about 17 mpg before.


My city is 13.5 (was 11ish before).

~JH
 

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My MPG went up a good bit after the SC.
I did a MPG test, driving both ways from Portland to Salem (Oregon) maintaining 70mph and was able to pull 20.9 going and 21 coming home.

-AC was on
-using premium fuel from PacPride (cardlock)
-reset MPG once vehicle was up to speed

Was getting about 17 mpg before.


My city is 13.5 (was 11ish before).

~JH
Yeah what JH said.
20-21mpg on the interstate (70-72mph) and 16.5-17.5mpg back and forth to work if I drive like a sane person.

Hope that helps...
 

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I've been consistently hearing about people getting better fuel economy with the SC.

Now if only I could use this argument to convince my wife that I need to SC my truck :D
 

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I used that argument with parents on my s/c 00 4runner and the gas mileage SUCKED
 

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city mpg went up a bit(1 mpg +/-) but highway is about where it was before s/c but this really depends on driving style.ballpark 13 city and 17 hwy.
a little faster really hurts mpg.
 

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I'm not sure how any of you are experiencing higher MPG w/ a supercharger.... it physically is impossible. You added more weight, a re-tuned computer to account for additional air by mixing in more fuel to get that power.... The best scenario is that because superchargers use centrifugal engine to drive the belts you will see very little difference from stock at lower rpms because the tune allows the engine to use the same air/fuel mixture at the lower RPM's.... at higher RPM's these numbers dramatically increase to account for the forced induction. It's pure physics.... there's no way of getting more power with better mileage unless there was a huge design flaw from factory as stock configuration.
 

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I'm not sure how any of you are experiencing higher MPG w/ a supercharger.... it physically is impossible. You added more weight, a re-tuned computer to account for additional air by mixing in more fuel to get that power.... The best scenario is that because superchargers use centrifugal engine to drive the belts you will see very little difference from stock at lower rpms because the tune allows the engine to use the same air/fuel mixture at the lower RPM's.... at higher RPM's these numbers dramatically increase to account for the forced induction. It's pure physics.... there's no way of getting more power with better mileage unless there was a huge design flaw from factory as stock configuration.

If it takes 50% throttle to go 75 mph with a 200 hp motor how much throttle is needed to maintain 75 mph if the motor makes 400hp?
The fact is that during most driving the engine makes the same as the NA motor. If it takes 100 HP to drive and maintain 75 mph with the NA it takes 100 hp to drive 75 mph with the SC, your just making the 100 HP with less throttle.

The weight (and a relatively small one added with the SC) will have no (measurable) affect on highway MPG, unless you want to try and measure higher rolling resistance on the wheel bearings and drag caused from tire deformation from the 80 additional pounds.

Its true that SC will cause drive losses. Its also true that the introduction of compressed air will reduce pumping losses.

The SC or turbo will increase mpg.....it has the POTENTIAL to make it worse (and will at WOT vs the NA) but unless you drive 100% of the time at WOT......

~JH
 

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Superchargers add parasitic drag on the engine due to the belt driven nature.... granted the Tundra S/C utilizes a low boost supercharger that probably has less friction allowing the truck to stay off boost through the lower RPM's. YES superchargers do compress air and theoretically will allow the engine to work less but the engine also is controlled by the computer that reads the sensors that end up compensating for the additional air w/ an equivalent amount of fuel.... more air = more fuel = more power = more fun!!! Anyways... if your flash allowed your computer to run more air w/o more fuel you would risk running lean and that always ends up bad with fried internals...

The only way I could possibly see the truck running better mileage is if the stock ECU runs the Tundra pig rich and when the super charger is added the additional air mixed with the un-changed fuel ratio the car then now runs stoich... this would be the only way the car would become more fuel efficient which also proves my initial claim that the vehicle would have had to been seriously off to begin with in stock format.
 

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I had a Grand Prix GTP (supercharged) at the same time my mom had a Grand Prix GT (NA). I consistently got 4-5 mpg better than she did. I know it's not a Tundra, but it's the same concept.
 

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I had a Grand Prix GTP (supercharged) at the same time my mom had a Grand Prix GT (NA). I consistently got 4-5 mpg better than she did. I know it's not a Tundra, but it's the same concept.
That's two different models of cars. There could be a lot of variables in there... differential ratio, transmission ratios, the motor itself, etc...


Anyway, people who actually have superchargers have answered that they have seen no change/slight increase in fuel mileage. This is real world stuff and not "in theory" postings - so the "in theory" posts that say otherwise can stop now.
 

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The only way I could possibly see the truck running better mileage is if the stock ECU runs the Tundra pig rich and when the super charger is added the additional air mixed with the un-changed fuel ratio the car then now runs stoich... this would be the only way the car would become more fuel efficient which also proves my initial claim that the vehicle would have had to been seriously off to begin with in stock format.
This has been the theory for most on this forum for getting better mileage after the SC. These trucks do run pig rich, as you put it, stock. The supercharger has a better tuned ECU flash from what I have been reading since it came out, and doesn't run as rich. There are still some who have taken it farther and ran a tuner from URD to get the A/F ratio to what they prefer.
 

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Hey TomP, go get a SC installed and see for yourself:D

Seriously though, all engines are programmed to make 14.7AFR during closed loop, even my SC Tundra; unless you have a stand alone engine controller. Reason being that is the optimum AFR for the Cats to word there best. If didn't have cats and you had a stand alone ECU you could raise the closed loop AFR and get a lot better fuel mileage. However nobody is going to change that for you because it is against the law; and if they did your cats would burn up. All the performance tuning is done in open loop during WOT (wide open throttle).

Superchargers add parasitic drag on the engine due to the belt driven nature.... granted the Tundra S/C utilizes a low boost supercharger that probably has less friction allowing the truck to stay off boost through the lower RPM's. YES superchargers do compress air and theoretically will allow the engine to work less but the engine also is controlled by the computer that reads the sensors that end up compensating for the additional air w/ an equivalent amount of fuel.... more air = more fuel = more power = more fun!!! Anyways... if your flash allowed your computer to run more air w/o more fuel you would risk running lean and that always ends up bad with fried internals...

The only way I could possibly see the truck running better mileage is if the stock ECU runs the Tundra pig rich and when the super charger is added the additional air mixed with the un-changed fuel ratio the car then now runs stoich... this would be the only way the car would become more fuel efficient which also proves my initial claim that the vehicle would have had to been seriously off to begin with in stock format.
 

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So I guess we can conclude that the Tundra in stock form runs overly rich and the re-flash w/ the S/C does in fact level out closer to stoich. I can see that w/ 7 lbs. Interesting.... gives me lots of ideas! :)
 
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