MPG w/ Stock Supercharger - PLEASE READ BEFORE VOTING

Okay guys, I'm curious as to what kind of gas mileage you guys with stock 1st gen superchargers get.

PLEEEEEEEEASE only vote if you have a 1st gen 3.4 V6 Supercharger so I can get accurate results.

Also, if you vote, please list any mods that may effect the mileage.

Lastly, please tag anyone you know on here who meets the criteria so I can get some feedback.

Thanks

 

19-21 with K&N, 31" A/T, 3" lift.

17-19 with those listed in addition to 2.2" pulley, URD 7th and 32" KM2's.

You have the option to stay completely out of boost 100% of the time with any forced induction engine.

 

@eon_blue

 

How?

 

Just monitor your boost gauge, depending on how much you open up your throttle during acceleration determines whether or not you go into boost.

 

I average about 17mpg total with my 3.4l v6, supercharged. On the highway if I cruise at 65-68mph I average 20mpg.

This is all with minimal boost being used, if I floor it into the 0-7psi range frequently (especially around town) my mileage will go down quick, which is to be expected.

 

Also I should mention, my supercharger is completely stock but I do have the TRD headers and exhaust which (in theory) should help with mileage a little as it allows the entire exhaust to flow more freely. It can also hurt my mileage more if I jet around town.

I've been meaning to do some fuel system upgrades with my s/c (7th injector and URD air/fuel calibration namely), not so much for mileage but to help the supercharger be more efficient and have less of a negative impact on my motor long term.

 

Where can you get a boost gauge with low PSI on them? All the ones I've come across are in like 5-10-15-20 increments. I'd like one that is like 1-10 or 15.

Where did you get TRD headers?

 

I have the TRD boost gauge, not sure if they still sell them since discontinuing the supercharger but it's worth a look...try www.trdshop.com. It reads boost from 0 -20 psi I believe, the stock 3.4l s/c only goes up to 7 psi so it's well within range

TRD discontinued their headers several years ago They discontinue everything that's fun

 

Well that sucks! I've never really done any performance mods to my truck, but I'm down for anything!

Also, have y'all ever changed the SC oil? I bought a kit to do it and I'm wondering how big of a pain it is. I was gonna buy the nose cone kit, but it's like $500+

 

You have the supercharger right? That's the best performance mod you can do to these trucks lol. I haven't changed the oil in my s/c yet but I don' think they recommend it until close to 100k miles, probably around the time you'd want to consider a rebuild anyhow.

 

Ha I'm already at 160k. I know the previous owner didn't change the oil, so I'll do that this weekend. Hopefully I won't have to take it off b/c I'm sure that's a pain. Is the nose cone kit a rebuild?

 

I don't think it's considered a complete rebuild to just do the nose cone, they sell rebuild kits through sites like LC engineering and URD, the rebuild kit will be for a Magnunson supercharger not "TRD", but the TRD one was always a Magnunson anyhow...just no longer comes with the TRD label on it.

Here's a stickied thread on the forum about rebuilding the 3.4l supercharger, it's a lot of info but it's a great read to familiarize yourself with the process...I'm reading through it bit by bit so I'll hopefully know what I'm getting into when the time comes, lol.

https://www.tacomaworld.com/threads/3-4l-trd-supercharger-rebuild.267610/page-15#post-12512062

 

Thanks for all the info man. I'm a newb when it comes to superchargers. I'll definitely do the oil change this weekend. Final question is a 2-parter:

1. if the belt breaks on the supercharger, will the engine still function correctly? Mine has the original belt on it and I have a spare in my truck, but I'm just wondering out of curiosity.

2. If my supercharger ever bit the dust, could I simply remove it and the truck run fine? I think I'd have to re-route the pipe for my air filter, right? Hoping that day never comes, but again, just curious.

Thanks!

 

I'm a complete noob to the boost game myself, no worries. I just got my truck less than 3 months ago, when I drove down to the dealership 3 hours away to look at it and buy it, I was surprised to find that it was supercharged, lol. The saleslady I was dealing with had no idea.

Anyway those are some great questions...ones I would like to know as well haha.
I did a quick google search for "if my supercharger belt breaks will my truck still run" and I got this hit from Cargurus regarding Pontiac cars, but it seems like the answer is yes...the truck will "run" but it will run horribly and you'll get terrible gas mileage. Basically it will run well enough for you to get it to a shop or back home but you'll have to repair it asap.

https://www.cargurus.com/Cars/Discussion-t16831_ds443729

As for #2, if the supercharger bit the dust you would have to replace it with the stock intake manifold and belts for the water pump, alternator, etc. since the supercharger pulley/belt runs those currently. Again I'm a noob with this as well so if anyone else has more info or a better correct answer, please chime in!

 

Thanks. The rebuild you posted doesn't seem overly difficult. I'm pretty mechanically inclined and my wife's uncle owns a garage, so I can always bug him for help and tools if I don't have what I need.

 

I've got the TT Supra MAF with URD fuel mods (FIC), an old Downey Off Road air intake with a dry Amsoil cone filter, water meth injection, 2.1 pulley, TRD headers, and a Gibson cat back.
I average 16-18 with 33's and armor but on the highway if I take it easy I can around 21mpg. I can tune it to get a little better mileage but I prefer more power.
I have been running it with no timing retard with the WI but change the tune to put back the retard when I tow my trailer (approx. 1000lb) for piece of mind.

I have about 60K on it with not touching it and it does not make any strange noises.

 

1. The engine will run but the belt also turns the alternator so that would limit how far you go ie. on battery alone. When I was tuning it years ago I would zip tie the bypass actuator open to tune the area where it would be on the threshold of transitioning to boost. I was bored and wanted to try it.
Say you throw a belt and have a spare but something happens to the S/C, you can tie open the actuator and drive with no boost, not real fun but doable.

2. You shouldn't have to re run the pipe since the position of the throttle body is in the same position NA or S/C'd.

 

You are correct with the exception of the water pump, it's driven off of the timing belt.

 

Thanks for the info. So if the worst happened and my SC bit the dust, I could still drive it far enough to fix it, correct?