do you need to run premium gas with super charger or not?

so far the answers I get is I have been told yes, maybe, depends, and flat out no

so what is the "real" truth about adding a super charger?

do you need premium octane gas?

"should" you upgrade the injectors?

"should" you upgrade to headers?

"should" you upgrade to better exhaust?

 

I live in the Denver suburbs, 5800'. I have a Grey supercharger with a stock pulley on a 2000 Tacoma. I don't have any fuel mods yet. I can run 87 (mid here) as long as the temperatures stay below 85° to 90°, above that I'll hear light detonation/preignition. Being a manual transmission I could drive around what causes the detonation (2000 to 2500rpm heavy load) when I was running 87. I wouldn't recommend anything but premium though. I only drive with 87 when I goof and hit wrong button on the pump, my other 2 vehicles run mid grade and sometimes I fuel before coffee. 87 octane comes with a drop in power and poor fuel economy, 2 to 3 mpg. I don't have the cooler thermostat from a Scion TC yet, more on that in the 2nd paragraph.

I had my current supercharger on 3 other vehicles besides my Tacoma. Most recent was a 1996 4runner, it had the same lift and tires with stock 4.10 gears and a manual, same as my Tacoma. I installed a cooler rated thermostat from a Scion TC (160°ish) and that was the only mods to the engine. I was able to run 87 octane without any detonation but the power and fuel economy was less then when using 91.

I had the supercharger in a 1993 4runner with a 3.4 swap from a 98 T100. It was an Automatic. With a cooler thermostat (the 3.4l TRD that was actually for a 3.4l) this thing could only run 91. If the fuel was poor quality you felt it. If the outside temperatures were above 90° the vehicle would have detonation around 2000-2500rpm, right where the Automatic always wanted to shift to. It was a pain to drive in the summer with the charger on, I removed it and drove N/A because of the detonation.

The superchargers 1st home was a 1991 4runner with a 3.4l out of a 2000 Tundra (really odd to find that in Colorado). This engine/vehicle loved the supercharger, it never gave me any issues. I was able to run 85 octane without issues.

Moral of those little stories, it depends on the vehicle. As for your other questions; you don't "need" headers, you don't "need" an exhaust, you don't "need" fuel mods. Will they help with performance, yes. Will you blow your engine because you don't have them, no. Will you need premium fuels? That will depend on the vehicle, there is no cut and dry on this, for some reason each vehicle reacts different to the charger.

I plan on adding the 7th injector kit to my truck in the near future. Having driven a truck before and after the upgrade I know it is worth it for power. The vehicle didn't have any detonation issues so I can't speak for much there. One final Note, I did mention my altitude for a reason. The air is more dense at lower elevation so this might cause a difference. Trips to 3k feet didn't make a noticeable difference other then power on my trucks YMMV though.

 

So I read none of this but regardless of what he said if you put on a super charger you don't have to run high octane but it is reccommended

 

https://www.tacomaworld.com/threads/tw-official-bs-thread.397428/

 

In the scary world of a 3.4l supercharger, possibly. 4.0l superchargers with your fancy larger fuel injectors and factory tuning...............

 

thanks for the detailed answer, that helps understand things better

here in Louisiana im driving in 90 degree plus weather 90% of the year with humidity in the 90's all year as well so I gather the answer on which gas it will need in my area is absolutely, yes I need to run premium gas if I am going to charge it. this is an unexpected added cost that must be factored into it and needing to add a cooler 170* thermostat was info I wasn't aware of but minor thing

 

So again I read none of this but if you are super paranoid about shit run fucking racing fuel at 110 octane if not fuck it just recommend 91 octane here in so cal

 

FYI - regular here is 87 octane and premium is 91 octane

and the 3.4 truck and computer system is untenable and much different and nothing like your 4.0 with tunable ECM

 

my 2 cents, you don't need to upgrade or use higher octane fuels unless you plan on racing the truck and being at higher RPMs a lot. Our engines stock compression ratio is 9.6:1. adding a super charger will change that ratio to a minumum of 10.9:1 with a 2psi boost (at max RPMs, reference this link). And according to this chart, you'll need to be running octanes higher than what's available at your average pump to prevent knocking.

butt hat is all at max RPMs. I don't think you'll be up there in the reds, so you don't really have to worry about it. use higher octanes at your discretion.

honestly, adding a charger will only improve your acceleration and engine revs with a light foot. you're better off just having a heavier foot.

 

Thays the point just run 91 it's another 20 cents you'll be alright

 

well isn't that what he said to do before you replied the way you did

 

Sure I'm not sure to tell you the truth it's reccommended to run 91 octane but not a huge deal if you don't your not going to hurt anything running 87 I just recommend 91 myself but it is not required

 

Bruh! That is what I said in a more conversational way. TRD recommended 91 but you can get away with less on some vehicles. Don't fight thinking, even if you're drinking.

 

Just run 91....come on its a small price to pay for safety and fun...my truck ran like shit before 91 octane and it pinged more

 

Sure you can "get away" with it but why would you ever risk running lean and hurting your vehicle.....

 

Haha that is signature worthy that is awesome sorry your post was extremely long and didn't feel like reading that much

 

running lean? that doesn't make sense octane is a rating to measure resistance to combustion due to high compression ratios (knock).

Also, your computer is actively adjusting fuel mix ratios at all times based on your O2 and mass air flow sensors, and unless your car has other issues, you will never run too lean or too rich. and running too rich or lean doesn't harm your engine at all. It just kills engine performance.

 

You tell him I read like the first 3 words but your right that other guy doesn't know what he's talking about

 

That's not true at all dude In Regards to never running to lean....in boost the ecu does not give enough fuel ...that's why people run the 7tb injector because these trucks run LEAN In boost....especially in closed loop 14.7 is too lean for wing under boost.....I don't know too much about the knock

 

Maybe you will never run too lean or too rich without a supercharger...but it's not the same with a supercharger and it leans out in high rpm and high boost and it's not safe