How'd this play out? There was a thread a couple of weeks ago when people were still experimenting. Does having these off improve mpg much?

IMO no

Made very little difference after 3 full weeks of testing..

In that time:

- Miles driven: 1,983 miles.
- Fuel used: 120.85 gallons (87-octane)
- Total cost: $238.91.
- Average MPG: 16.41 MPG
- Cost per mile: $.12048

By comparison, the mileage driven prior:
- Miles driven: 1499
- Fuel used: 92.621 gallons (mostly 87)
- Total cost: $195.19
- Average MPG: 16.18 MPG
- Cost per mile: $.13021


Here's my current log (http://home.socal.rr.com/mozzy/RX8_mpg_log/RX8_log.htm).


So there you have it folks... While there is a difference, it is negligible, because minor daily temperature variations are enough to cause just as much of a difference.

squid
have you seen a differnece between using 87 or 92

I am on my 4th tank and drove with the DSC off for one of the 4.

1st - 19.5 Drove like granny - DSC on. 50/50 driving with air.

2nd - 18.1 DSC on - 50/50 driving with air.

3rd - 18.6 DSC off with same driving conditions.

4th ???? DSC on. Based on my current mileage fuel gage, it looks like it is going to be in the 18 range. The was the first tank I really started getting on it.

from one fillup to the next fillup cannot detect any small increase or decrease simply because the level on each fillup can be slightly more or less than the previous fill plus there are small but present factors like temperature variances. I think it takes several tanks to really tell if something is affecting overall mileage. My last few tanks I've been trying Shell - filled up at the same pump, similar weather, hopefully similar total gallons in the tank at fill, etc. Has not warranted spending the extra (.08) per gallon versus my normal gas. I've found that with DSC off it may have increased a small (1mpg) amount.

It seems that those that have low MPG - say in the 16 - 18 range - have trouble increasing their mileage no matter what they do. I sure have to think that either the gas is crappy in those regions - or that the ECU on some cars is just running rich almost all the time for some reason. Some differences can be driving habits and city/highway mix but certainly not all of it. My single worst run was in the 14s but that was mostly WOT 2nd gear with a lot of braking between the WOT bursts.

On my next tank I'll got back to super from the non-Shell station and keep that up for the next few tanks, with DSC off most of the time, to see what happens.

All I know is the car seems a hell of a lot faster with DSC completely turned off (holding down for 5 seconds). Is there anyway to disconnect it? Like pull the fuse.....

Tried it, no difference.

Really? Maybe it's just me but my buddy riding shotgun even thought it felt faster...

Could be dreaming

Originally posted by mikeb

have you seen a differnece between using 87 or 92

i am interested in the same question??

Originally posted by mikeb
squid
have you seen a differnece between using 87 or 92

if you saw my log, you would know that I have not used 92..

I only filled up once with 91, so my car has used two tanks of supreme gas, the original tank and my first fillup. The miles driven on supreme were all "break-in" miles.

All other miles were driven on 87. I am currently at 3800 miles on 87.

If I were to try and compare my experience between the two gasolines, I would say I have noticed no difference.

When I hit 4000, I will switch to back to supreme for the next 3000 miles or so.

I will try to keep my log updated with every fill-up, so keep the link handy if you want to check up on my progress.


T

thank you
I have used 91 thats what I meant sorry

Originally posted by Squidward
Here's my current log (http://home.socal.rr.com/mozzy/RX8_mpg_log/RX8_log.htm). Squid,
Thanks for the chart I've been tracking my own (up to 4600 miles so far). I will post it though the results are not pretty. :)