Switching from 93 oct tune to 87 oct tune

[Grey Ghost]

Okay, let start off first by saying I've searched for this and couldn't find a straight answer. This is probably a non issue, but I want to switch from my current 93 octane tune down to a 87 oct tune to help my wallet out on gas mileage.

I've currently got a 3/4 tank of 93 octane gas and I wanted to know, do I have to run my tank empty first and then put in 87 octane gas to run my 87 octane tune? Or can I just switch from my 93 octane tune on the tuner to my 87 octane tune now even though I have 93 octane gas still in the tank. I mean that can't hurt my engine right?

Just need some guidance on the best way for switching down tunes. If anyone could let me know that would be much appreciative.

thanks!

 

[jgilbert04]

I have switched down my Brenspeed 93 to the 87 tune before and had no problems. I didn't see any savings though. My gas mileage actually got worse, but that was winter blend here in Indiana, so it may be different for you in Missouri.

 

[Captainstr8edge]

There should be no problems.

 

[Franchi]

Running 93 on a 87 tune should be fine. Running 87 on a 93 tune could def cause issues though.

 

[keeno]

I am about to do the same thing in mine..for commuting while the gas prices are spiking again. If I go to the track, I'll load the 93 tune back in it.

 

[Captainstr8edge]

I am about to do the same thing in mine..for commuting while the gas prices are spiking again. If I go to the track, I'll load the 93 tune back in it.

Just make sure u fill it with 93 twice before you do that or you could have issues.

 

[keeno]

Its actually a 91 octane tune I have now, but all the premium around here is 93.

 

[JEWC_Motorsports]

I wish there was a definitive answer to switching down. I have read alot where people have lost mpg by switching down, then other say they have gained. I switched down and i lost mpg. With my 93 tune i was getting 20.3 mpg on the highway, thats mostly what i drive on. On my 87 tune the mpg's went down to 18.7. I think its because i got so used to how it acts with the 93 tune that when the 87 tune is in im trying to force it to act like it did before. Hence burning more fuel to get that same feeling. Maybe its just me.

 

[Captainstr8edge]

I think it really depends on the tune. You will also get a loss of power running 93 on an 87 tune, so you really can't go by the first tank.

 

[2010GT]

Hey Grey, You get any hail damage there from the last storm?

 

[Sky Render]

Running 93 on a 87 tune should be fine. Running 87 on a 93 tune could def cause issues though.

This is correct.

You'll have no problems running 93 octane on an 87-octane tune. It would be like dumping premium fuel into a base-model Ford Focus. It gives you no benefit whatsoever, but the car will still run fine.

 

[gmantheman]

I just switched from Amazons 91 tune to American Muscles 87 street tune. Around town I can't really tell a difference performance wise but I will monitor the MPG. With all of my 91 tunes (ATS, AM, DMP) I was getting 18.5 to 19.

 

[Grey Ghost]

Thanks guys! Guess it sounds like it shouldn't be a big deal.

2010GT - We did get a lot of hail and it started coming down as I was speeding towards my garage to get my car put away. Luckily the bit that hit my car didn't do any damage.