Cristo SS/TC

09 SS/TC with LDK swap with just over 3k miles, ZZP intake tube/air box mod, 3" MPX catack. No tune yet.

Only averaging 21.5-22.5 mpg. I commute to work 75% hwy 25% street. I stay out of boost a majority of the time and stay around 70-75 mph on the hwy. Occasionally do some 2nd or 3rd gear pulls.

Any Ideas? I am getting it tuned, will that help?

Thanks, Mike

Snail_SS

iTrader: (3)

It should help getting it tuned

Devin86

I would hope a tune helped even when I pull day after day I never see under 24mpg haha

footballplaya3k

iTrader: (1)

You have pretty much the same setup as me, and we drive about the same percent highway and city. I get between 26-27MPG overall. I get at least 23MPG in the city, hopefully a tune fixes it for you.

ECaulk

iTrader: (6)

What are your fuel trims?

Snail_SS

iTrader: (3)

Yeah you could be running rich

Cristo SS/TC

Not sure. Its not tuned yet, and even when it was stock LNF I was getting same mpg and that was with a porous block. Waiting for my GMS1 harness kit to come in. Once I get the tune installed I will update the mpg after a few tanks of gas.

Thanks, for the replies!

Sl0wbaltSS

Slow it down, don't haul ass everywhere. do 67 on the freeway, Doing that I avg 23.5 mpg avg.... Tuning it won't get you much. If anything it will lower your mpg cause you will want to be flooring it everywhere.

ECaulk

iTrader: (6)

There is something other than the LDK causing the issue then, if you had the same mileage prior to the LDK install I would look into other things. See if you can find someone that can log your LTFT or better yet buy an interceptor gauge so you can monitor the LTFT, Knock Retard, Lambda etc.

Also ignore the guy below 98% of what his says is bullshit and wrong.

Devin86

If he's getting 23.5 going 67 he's doing somthing wrong lol I've never seen under 24 and I drive every day 40+miles city highway races pulls so if it's under 24 check somthing.

umrdyldo

iTrader: (1)

Over 30mpg at 65mpg should be more than achievable.

exninja

iTrader: (1)

My mileage with LDK is not noticeably different than pre-LDK.

footballplaya3k

iTrader: (1)

I get about 35mpg crusing at 60-65.

Cristo SS/TC

OK, so I installed my ZZP tune and GMS1 sensors. No change in mpg. I will be getting a gauge soon to monitor my LTFT's. I think it has something to do with the in tank fuel pump. The fuel gauge will fluctuate even with a full tank. I heard there was a recall or TSB on a sensor that is on the top?

Dipped_Cobalt

35mpg? seriously?

umrdyldo

iTrader: (1)

Yes I think most of can see 35mpg at 60mph cruise on a flat surface. No issue at all actually.

Dipped_Cobalt

awesome. I need to try!

umrdyldo

iTrader: (1)

Lol, yeah well if you push the gas it will get about 15.

It's all in the right foot.

Especially tuned. We go from a 0.95 lamda in the mid range to 0.88 or less and use a lot more fuel tuned. But that's ok. We have other ways of running ethanol and getting better gas mileage and saving money.

doubledamageXX

i was getting 450 miles a tank on my way from Chicago to Florida. Average speed including stops was 60+mph. Custom tune by PWerks. I agree, i think tune will help unless you plan on going all out. So i guess a better phrase would be a tune MAY help. lol

Cristo SS/TC

OK. So I installed installed my ZZP tune with the 3bar sensors. Wow! what a difference in power. They say the tune is 22-23 psi but I get to 25psi WOT. No change in mpg, getting 21.5 mpg even staying out of boost. I purchased Dashcommand and an OBD2 wifi adapter so I can monitor the fuel trims, MAP, MAF, timing, ....etc. I will post the results as soon as I can log them.

Thanks

footballplaya3k

iTrader: (1)

What RPM do you shift at? Are you in boost or near 0" vacuum during normal driving?

If you shift at low RPM and use boost or extra gas pedal to compensate for lack of power you will get terrible MPG.

Cristo SS/TC

I try and shift around 22-2500 RPM's. If I do some pulls I take it up to 3500 but I dont do that often due to the poor mpg. Normal driving I am in vacuum.

Thanks

ECaulk

iTrader: (6)

Your ******* it, that's why you have poor gas mileage. Shift closer to 3500 cruise around 2250-2500 if you can.

umrdyldo

iTrader: (1)

I don't think I could drive harder and get 21mpg.

I get 24 and I consider that horrible for this car.

ECaulk

iTrader: (6)

Even with driving in the mountains and getting on it I don't usually see less than 23mpg. It honestly sounds like the OP is trying to shift early to save gas but is actually wasting gas since he's not hitting the sweet spot