My edelbrock gas mileage is amazing

[taiguy]

I'm still working through my setup to see if there's any obvious problems.

Stock I was getting around 29 mpg. With the edelbrock supercharger I've been getting roughly 20 mpg. I would love to see this 25-28mpg that others speak of.

[azynneo]

Originally Posted by taiguy

I'm still working through my setup to see if there's any obvious problems.

Stock I was getting around 29 mpg. With the edelbrock supercharger I've been getting roughly 20 mpg. I would love to see this 25-28mpg that others speak of.

I guess it's subjective if you drive like a madman you would probably get like 5-6 mpg anywho.

[taiguy]

Originally Posted by azynneo

I guess it's subjective if you drive like a madman you would probably get like 5-6 mpg anywho.

Disagree. I'd say it's pretty objective.

What annoys me is that my 3.6L outback just averaged 25.4 mpg over the last tank. It's a bigger heavier car that has better fuel economy than the BRZ now.

If I want to play in the sub 20 mpg range, I'd look for something else. My buddy's mercedes has a 5.5L V8 twin turbo with twice the power and puts down the same fuel economy. Makes no sense.

[why?]

Originally Posted by taiguy

I'm still working through my setup to see if there's any obvious problems.

Stock I was getting around 29 mpg. With the edelbrock supercharger I've been getting roughly 20 mpg. I would love to see this 25-28mpg that others speak of.

It is winter now, do you have winter tires? Who did your tune? Winter gas can get different gas mileage. Do you waste gas by letting your car "warm up?" Do you do lots of city driving? What rpm are you shifting at in normal traffic? How hard do you slam on the gas pedal from a stop?

Colder air can actually increase power meaning much more fuel is needed too. There are so many different reasons for fuel mileage it is crazy. Most come down to personal driving style or your specific location and driving routes.

[mrg666]

Reading the comments, it is clear that there is a significant (20-30%) loss in fuel efficiency with Edelbrock and, probably, other twin-screw superchargers. This is consistent with the dyno charts showing twin-screws providing more power in the lower rpm compared to centrifugal superchargers giving more power at higher rpms. If you want the instant low-rpm power with twin-screw supercharger, it will burn gas for it. There is nothing surprising here, makes sense to me. Still better than a 370Z or equal to Cayman. Not bad at all.

[ajcarson11]

I'm running twin-screw Sprintex 210 and saw my fuel economy go from 30mpg to 26 (combined). Not all twin-screw systems rob fuel economy -- I can get 28/29mpg if I try on the interstate still.

I do agree that with Centrifugal systems you end up using less power, as you spend less time dailing driving at high RPM, than in a twin-screw system where you're always in the strong power band.

[taiguy]

Originally Posted by why?

It is winter now, do you have winter tires? Who did your tune? Winter gas can get different gas mileage. Do you waste gas by letting your car "warm up?" Do you do lots of city driving? What rpm are you shifting at in normal traffic? How hard do you slam on the gas pedal from a stop?

Colder air can actually increase power meaning much more fuel is needed too. There are so many different reasons for fuel mileage it is crazy. Most come down to personal driving style or your specific location and driving routes.

My BRZ is only a summer toy. The e-force went on May 2015, and have experienced piss poor fuel economy since then. I've used 3 different Edelbrock tunes, and have a 4th sitting in my inbox waiting for the snow to melt.

Everything else you're asking about is controlled as driving habits and behavior haven't changed. It's not like I went from only highway driving to stop and go after getting the e-force installed.

If everyone was getting 17-20 mpg daily driving I'd suck it up and say it's a tradeoff you'd have to consider before putting this kit on. The fact that there are plenty getting far better than myself and OP leads me to believe something else is going on.

Install error? Maybe... but I've checked everything I can think of, and everything that's been suggested in the massive FAQ thread as well as from Topher at Edelbrock. Nothing in my logs suggest a vacuum leak now however, that didn't stop my car from throwing high idle error codes on the EO CARB tune.

My current bet is there is something wrong or physically different with my car which is causing a material difference. OP may have an installer error, or same physical configuration that wasn't captured by Edelbrock during their development. All I've been asking for is places to look and so far everyone's been scratching their head.

[Xxyion]

I honestly wouldnt go that far to say there is something wrong with your car. Tune (even though you said you have a good tune) still can determine a lot. A big reason i'm getting such good mileage is because ever since getting the kit on i've been babying it. My Tune isnt complete yet so i rarely go above half throttle.

I'm pretty sure when my tune is complete and i can start pushing the car harder i will probably be getting 20 MPG. As of now i drive the car as slow as if it was stock and rarely hit 4k RPM. Thats going to drastically increase my MPG.

[taiguy]

Originally Posted by Xxyion

I honestly wouldnt go that far to say there is something wrong with your car. Tune (even though you said you have a good tune) still can determine a lot. A big reason i'm getting such good mileage is because ever since getting the kit on i've been babying it. My Tune isnt complete yet so i rarely go above half throttle.

I'm pretty sure when my tune is complete and i can start pushing the car harder i will probably be getting 20 MPG. As of now i drive the car as slow as if it was stock and rarely hit 4k RPM. Thats going to drastically increase my MPG.

Same and same.

[Xxyion]

Originally Posted by taiguy

Same and same.

What tune are you going with? I have a Delicious tune that is being custom refined to fit my car. If you are on any sort of OTS tunes that might be why.

[taiguy]

Originally Posted by Xxyion

What tune are you going with? I have a Delicious tune that is being custom refined to fit my car. If you are on any sort of OTS tunes that might be why.

Edelbrock CARB EO v3



On the left is my H6 outback, and on the right is the BRZ with e-force. it's a head scratcher.

Mike at CSG is stumped. The calibration guys at edelbrock are stumped. There aren't even any shops in the area, Colorado, that can help troubleshoot.

[Xxyion]

I've heard from A LOT of people that there are issues with the CARB tune. Granted it's all word of mouth and i have no experience from it myself. However it was enough for me to go with a Delicious tune. I'd hate for you to spend 350$ on a new license so i wont urge you to switch your tune but part of me thinks that will fix your issue.

[bfrank1972]

Originally Posted by ajcarson11

I'm running twin-screw Sprintex 210 and saw my fuel economy go from 30mpg to 26 (combined). Not all twin-screw systems rob fuel economy -- I can get 28/29mpg if I try on the interstate still.

I do agree that with Centrifugal systems you end up using less power, as you spend less time dailing driving at high RPM, than in a twin-screw system where you're always in the strong power band.

It makes sense, both the centrifugal and sprintex 210's are making less power than the tuned TVS blowers in the mid-range. Aside from inherent inefficiencies turning of positive displacement blowers vs centrifugal (not that big of a deal), you're just seeing power differences. Bigger blower with bigger mid range power = less gas mileage. Smaller blower like the 210 or a centrifugal with less mid range power = better gas mileage.

[CSG Mike]

Keep in mind, it's MUCH easier to accelerate faster with the Edelbrock kit on.

In instrumented testing where rate of acceleration is controlled, you do not see a 30% fuel economy loss.

It's very easy to unintentionally accelerate faster when you have more torque available. Using the V8 example above, you should see how the throttles are mapped vs the accelerator pedal; it's VERY non-linear down low.