Two questions about spark plugs and fuel economy.

[sunwolf]

So I ran my SHO with LMS 93 tune only for awhile then switched to 3bar 160tstat tune and saw a decrease in fuel economy by about 2 mpg. I thought it was just because it made it a little faster and I was pushing it a little harder but when I put the car back to stock to take it to the dealer I ran the rest of the day tune only and my mileage got better while I was still driving it hard. Are we expected to have a decrease in mileage with tstat and 3 bar? Does LMS do data logging like unleashed where we send in some data and get an updated tune?
Next question is about spark plugs. Can I buy the same plugs LMS sells at a local shop and do I need a new tune for them? Are stock plugs on a 14' just as good (I heard 13+ switched to .030 gap but I'm not sure)?

[SHOnUup]

Livernois plugs I got were Motorcraft sp534 pre gapped.

I also lost a couple mpg's with 3bar. I think it's because you get the turbos working at a lower rpm, thus sucking more gas. Their "tweaked tune" would be going back to one of their many non 3bar tunes. As I talked to them at CAD, the 4× tune came from extensive dyno pulls on Dave's car and it's a tamed down version of his a**ripper tune. They have a bunch of tunes on file to choose from as I was told. They push these updated tunes as they feel they are the best all around for speed and longevity.

Rich

[navbtcret]

So I ran my SHO with LMS 93 tune only for awhile then switched to 3bar 160tstat tune and saw a decrease in fuel economy by about 2 mpg. I thought it was just because it made it a little faster and I was pushing it a little harder but when I put the car back to stock to take it to the dealer I ran the rest of the day tune only and my mileage got better while I was still driving it hard. Are we expected to have a decrease in mileage with tstat and 3 bar? Does LMS do data logging like unleashed where we send in some data and get an updated tune?
Next question is about spark plugs. Can I buy the same plugs LMS sells at a local shop and do I need a new tune for them? Are stock plugs on a 14' just as good (I heard 13+ switched to .030 gap but I'm not sure)?

How long ago did you switch tunes? If it was recently you will see a decrease because of the winter blend gas at the pump. My fuel mileage stayed about the same going from the 2 bar tune to the 3 bar tune.

I would pull the plugs to check and set the gaps. They are probably around .035 from the factory, at least that is where mine were on my 2013.

[Brucelinc]

I interesting that you guys saw worse mileage with the 3 bar tunes.  If anything, my mileage actually increased slightly after installing the 4X/3 bar tune.

It is possible that the reason my mileage didn't drop is just because most of my driving is highway rather than city.   When I really push mine, I definitely see more boost at lower RPM and that would, of course, use more fuel.  However, under part throttle cruise conditions, where no boost is being used, the changes in ignition timing likely improve mileage.  As we all know, mileage will vary based on your driving habits. 

[SHOdded]

Strange.  You should be able to maintain or improve the mpg with the 3bar tune.  The fans do run a lot more with the cooler tstats, that could possibly cause a minor drop.

Shouldn't need to get new plugs just yet, unless you are already at 25-30K miles.  The spark plug gap on the specified SP534s in the OM for 2014 is still 0.033-0.037.  Would have to check new plugs to see what their gap actually is.

[SHOnUup]

^^^3bar does induce more use of the happy pedal:P

Winter blend is a valid point also. Any extended warm up time in the cooler temps too.

Rich