I was wondering if anyone has any data about the MPG of performance chips? I have a set in mine and the MPG has taken a nose dive, big time. Do these chips really make that much of a difference? I am almost at a half of tank and only 90 miles. I have not really put the pedal to the floor since I put this tank of gas in, this is the second tank since chips went in the car. If this is standard MPG with chips, I really can't justify the little performance gain over the cost of fuel.

 

That does not sound good. I was considering chips. Are these from the guy in Michigan?

 

Maybe the earlier cars benefit from chips, but I am told by almost everyone I respect in the 928 community that they do almost nothing for the later cars. If you are using that much gas (10 miles per gallon), you are going to cause yourself some problems with at least plugs and cats, and perhaps other engine components as well......

 

I am still doing around 11-12liters/100 Km (20 miles a US gallon) with the chip and RMB.

 

Were the chips installed with the ground strap disconnected (LH Reset)? Sounds like you're running VERY rich. If you disconnect the ground strap for a minute or two, and try again, it might help. The LH is supposed to be "adaptive."

After I installed my SC, the car idled very rich, with no hunting on the AFM. I reset the LH, and drove placidly for several days, in an attempt to establish a conservative baseline. I have no idea whether this worked, other than my idle is now proper, as evidenced by the AFM.

I average somewhere around 13-14 MPG, which seems to be low compared to other folks, but probably 60% of my driving is around town, and I tend to floor it onto the on ramps, since with traffic it's about the only chance I get to feel the blistering acceleration.

 

Bill,

There has to be something else going on if you are using Autothority Chips. I have been selling them for over 8 years and have never heard or experianced what you are experiancing. If you are using some of the other brands or Ebay chips then I have no experiance with those and I guess anything is possible.

 

I have chips and get bad mileage - but - I do not have lengthy highway mile intervals to measure for good comparison to others. How do you compare city driving to others' city driving? Anyhow, I too am displeased with how quickly the fuel guage falls with very little driving. I will seldom pay close attention, otherwise I will do the economic analysis and drive boring cars all of the time.

Chips are supposed to make a difference for 85 - 86.5 cars. You can simply put your stock chips back in, and if you cannot feel the difference, you might as well keep things stock.

Not sure how anyone is supposed to be gentle on the accelerator pedal with these cars and get good mileage. Too much fun to go vroom vroom.

 

I have Autothority chips in my 88 and it averages about 22mpg in mixed driving....

 

I took ground strap off when I put the chips in the car.
I do not have a rich smell.
The chips were bought from a friend for $50. He got them from Ebay. I do notice a difference but it's not worth the gas. They are not Autothority chips because they do not say it on them, I am correct in saying that? Autothority has their name on the chip?
Even with a mixture of city and highway, I will get about 15-17 MPG or better. Now I'm getting about 10-12 MPG.
I guess there is a difference between the chips. I wish I had a set of Autothority to compare to. Anybody have a set they're not using now I might compare them to?

 

Officially yes, unofficially, no. All it takes to replicate a set of chips is an EPROM blower. It is very likely that yours is a copy of Autothority, since Autothority is THE most common 928 performance chipset out there.

I think my mileage has been under 15, but nowhere close to 10.

Maybe you have something different than Autothority. Are you sure you haven't been "Testing" your chips with additional leadfootedness?

 

[QUOTE]James-man
Maybe you have something different than Autothority. Are you sure you haven't been "Testing" your chips with additional leadfootedness? [QUOTE]


I did before I filled up this time.

 

Bill,
FYI - I have the Autothority chips and I average 17 MPG in mixed (highway/city) driving, with a lot of "Testing".

Sounds like something is up with your chips.

 

I noticed my MPG went up slightly after installing the performance chips. I easily get 20+ mpg in highway driving.