AFM delete - gas mileage

[mrwmaw]

I have just had the magnaflo axleback installed, car tuned, and airraid cai installed. I seriously want to have the AFM shut off but the place I had the work done from suggested it would seriously effect my gas mileage. I am curious what everyone who has done this is experiencing gas mileage wise. I have seen a few that have said 1 mpg but wanted a broader response. I have searched numerous threads and haven't found the answers I am looking for. I'm sure some of you are thinking if you have to ask, then you don't need it. I have a long commute to work and have no problem paying extra for gas, but don't want to get 9 mpg. Any help is appreciated.

[RedJewel2SS]

i lost about 1-2mpg on the highway, no noticable effects in the city cuz i'm kind of a lead foot.

[Mike@DS]

Yeah, I am not convinced that it adds that much mileage in the factory programming, obviously driving style will be the biggest contributing factor.

We have found in the trucks, we can see 2-3 MPG gains from optimizing the use of AFM, but we have never played with it in the Camaro, mainly because you should not be buying these cars looking for mileage!!

[mrwmaw]

I went for the plunge. I retuned the AFM out and am a much happier man. I have no regrets. It is a totally different car and drives the way a camaro should. I have seen no mpg difference yet but have only driven it to work once. Thank you for your guys response.

[ron10]

i have the AFM and i only get 14mpg.i don't think it is all it is cracked up to be.

[06MonteSS]

nah, it ain't... well, it may be, if you do 90% highway driving...

but with my 50/50 city/highway driving, I have had it off for 4 years now in my Monte SS... and get better mileage with it off...

[Mike's LazruSS]

A friend of mine who did it...... if you know what I mean.... did a short test with cruise set at 70, before and after the delete, and lost about one half mpg. Just do it.

[myold88]

You may or may not lose a mile or two MPG but you definately will lose your factory drive train warranty if you disable your AFM. Since you already did a tune you have nothing to lose at this point. Not worth it in my opinion.

[RedJewel2SS]

Originally Posted by myold88

You may or may not lose a mile or two MPG but you definately will lose your factory drive train warranty if you disable your AFM. Not worth it in my opinion.

no it doesn't... having a tune may, but just deleting the AFM can't

to void a warranty it would have to be a direct cause of the failure, and there is no way they will pin a voided warranty for anything on the AFM being disabled. they will pin it on having it tuned.

just revert to stock before having any work done and guess what, no performance tune on the computer when in for service means no voided warranty.

[06MonteSS]

Originally Posted by myold88

You may or may not lose a mile or two MPG but you definately will lose your factory drive train warranty if you disable your AFM. Since you already did a tune you have nothing to lose at this point. Not worth it in my opinion.

NOT!!! hahaha...

having a complete tune, maybe... but just disabling the AFM, no way...

you can drive around the whole time you own the car in 4th or 5th gear, and the AFM will never kick in... so therefore, you've effectively "disabled" it...

that will do nothing to your warranty... hahaha...

[myold88]

Originally Posted by 06MonteSS

NOT!!! hahaha...

having a complete tune, maybe... but just disabling the AFM, no way...

you can drive around the whole time you own the car in 4th or 5th gear, and the AFM will never kick in... so therefore, you've effectively "disabled" it...

that will do nothing to your warranty... hahaha...

I think I'll take the advice of my service manager and others who disagree with you. Even if reversed, GM can tell if any tune was done. If you want to fight a denied warranty claim with GM, I think we'll know who the last laugh is on.

[Sherwood SS]

Tuned mine out with the preadtor and my mileage is the same as it was before. I have not changed my driving habits either. DO IT!

[Dave Coyle]

I've had mine tuned and really have not been on the highway for a long run but have driven back and forth to work with 5 stop signs in the 25 mile trip to work and a few times have run her hard up to 100 mph and then backed down to 55 and am averaging 18-19 miles per gallon. I am doing the C5 trip so that will give me some numbers on the highway. I just broke the 1500 miles mark so they say milage gets better after 3000 miles. Time will tell.

[RedJewel2SS]

Originally Posted by myold88

I think I'll take the advice of my service manager and others who disagree with you. Even if reversed, GM can tell if any tune was done. If you want to fight a denied warranty claim with GM, I think we'll know who the last laugh is on.

this argument has been thrown around so many times.

of course the service manager is going to tell you they can tell if a tune was done.

yet their is no concrete proof that they can tell if there was a tune on the car before, if the stock tune is on the car when you take it in for work.


i discussed this with my service rep, i even showed him my programmer and how it worked. because i was getting my oil cooler gasket fixed... i stopped him before taking the car in the back and said i need to revert the computer back to the stock tune if he is going to plug the car into his computer.

i showed him my programmer, restored my stock backup, he took the car to the back, and said nothing else of it! all he said was they had difficulties pulling the oil cooler off because my long tube headers were in the way... yet they didn't void the warranty because neither the tune nor the headers were the direct cause of the gasket leak


if someone is dumb enough to leave a "non-stock" tune on the car when you go in for some kinda serious internal engine/tranny warranty fix, of course they're going to stamp a big "DENIED" on the warranty claim.

everyone knows to put the stock tune on the car before going to the dealer because there may be updates that they will upload right over whatever is on the computer without even telling you they did it