MPG on your 3rd Gen?
- Thread starter clarkie470
- Start date
What's this "secret" y'all are talking about?
eep:
It's a joke.
VH200 Whole Room Heater – Vornado
Somewhere there is a thread on here talking about the Deckplate mod and somehow the Vornado gets brought up. The Deckplate mod is a cold air intake mod. It helps the engine pull in more air which equates to a small performance improvement. It has been dyno'd by several people showing the improvements to both normally aspirated and supercharged 5VZ-FE motors. It helps to also install a freer-flowing exhaust to take advantage of this.
There are a lot of people who do not think the Deckplate does anything at all. So, they make fun of it.
I have a scan tool that shows live data and the IAT (Intake Air Temperature), which is measured right at the MAF, always shows ambient air temps. It's never engine bay hot air as a lot of folks seem to think. It pulls air from right behind the right side headlight. The same scan tool also shows an increase in the Long Term Fuel Trim (LTFT) with the Deckplate open, which means that the extra air is causing the ECU to increase fuel delivery to keep the engine at Stoichiometric ratios. My AIRAID MIT (Modular Intake Tube) which replaces the stock intake tube between the airbox and the throttle body also improves airflow along with a corresponding increase in the LTFT metric. The combination of the Deckplate + Airaid MIT + AFE High Flow air filter + Exhaust adds up to 13-16+ % in LTFT. My LTFT sits at 19.5% at idle and at cruise. It all adds up to a noticeable difference in performance. There is more useable midrange power and grunt below 2K RPM in my experience. Is any of it necessary? No. But, I enjoy the extra performance.
The elbow mod also is a cold air intake mod.
Hope this helps clear things up.
Cheers.
I paid $3.47/gal yesterday in the Portland, OR area. Gas is cheaper in the middle of the country. And, your driving isn't what I would consider City driving, which is why you are getting the numbers you are getting.
Happy Holidays.
jross20
New member
That's funny, I wonder where the fan came into the equation. On a side note though I've actually been thinking about doing both of those mods. If nothing else the airaid intake cleans up the engine bay.
Is that the same thing as doing the intake silencer removal mod? Does it sound any different in the front?
Airaid is better since it is mandrel bent and comes with the proper vacuum hose fittings, etc. Same loud sound with the deck plate open under hard acceleration.
Hope this helps.
Cheers.
phattyduck
Elite Member
Something is wrong if you are getting such a large LTFT... The MAF should be correctly sensing the extra air, so fuel trims should still be fairly close to 0% if all is running correctly (I have a deck plate, Airraid tube, but not exhaust and LTFT is always <+/-5%). If you are running higher ethanol fuel, different injectors, etc. then we can talk...
-Charlie
I reset the ECU this morning since I made a change to things (for science) and STFT instantly went to 19.5%, followed shortly by LTFT hitting 19.5% and STFT cycling through much smaller numbers for the in-the-moment fuel changes, which is my understanding of how things work.
Just for fun, I just went out to the truck just now, started 'er up and added voltage to the MAF output with my SMT-5 piggyback, which will make the ECU believe there is more air entering the engine, which there is versus a stock motor, and the STFT and LTFT metrics reacted accordingly. My LTFT now sits at 14% for instance based on how much "Air" I added to the MAF reading, which caused a reduction in STFT which was then corrected in the LTFT map in the ECU. I can watch the AFR reading cycle from lean to Stoich as the stock ECU figures things out.
I believe the conventional wisdom is to get LTFT near zero with tuning when you make modifications that affect your AF/R. I have been lax in my duty and letting the Stock ECU deal with the extra air.
Underdog Racing Development make a MAF calibrator for just such reasons and they have dyno'd the results.
jross20
New member
I love the wording of "finding" horsepower.
"Yep here it is billy, just hiding back behind here"
:tongue:
Rushthezeppelin
New member
Yeah seems like super slow working sending units is fairly common. Mine takes 20+ minutes to show full after I fill up.
brillo_76
Elite Member
What year are these gas gauges acting up? For some reason, the late models 01 and 02 are losing their grounds.
Some members ran a new ground from the tank up through the unplug cover to the chassis it seems to be fixing some of these gauge issues.
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Some members ran a new ground from the tank up through the unplug cover to the chassis it seems to be fixing some of these gauge issues.
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brillo_76
Elite Member
All my 97 and 98 rigs will go to fuel in less than 5 minutes. They slowly move up but somethings wrong if it takes 20 minutes.
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JoeT4R
Senior Member
I've been getting about 12.5-13 miles per gallon lately. Could be due to the brutally cold temperatures lately or just the winter fuel. I was using E15 for about 2 months straight but mileage was worse and regular 87 has been coming down in price and catching up to that of E15, so I switched back to regular 87. No sense in running E15 if it's the same price as regular and I'm yielding worse mpgs with it.
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shadow247
New member
I get about 14 to 15 on the highway depending on how hard I am driving. If I can keep it under 80, then I get 15, but if I stay over 80 for more than an hour, it dips into the 13 to 14 range...
285/70/17 Cooper STT PRO E load, 4.30s. Sliders, Savage Skids. 210k miles.
I get 8.5 MPG towing a 3200 lb camper.
285/70/17 Cooper STT PRO E load, 4.30s. Sliders, Savage Skids. 210k miles.
I get 8.5 MPG towing a 3200 lb camper.
Rushthezeppelin
New member
So I've now run two full tanks of 87 E free through mine. First tank cam out to a tad over 16mpg which I was somewhat surprised about. Granted that tank was very very city driving and the last of it was spent in 4hi going about 20mph for a while navigating the storm that nobody seemed to forecast here in Denver. Second tank I'm just about finished with and was almost all mountain driving. Unfortunately the place where I get my 87 E free was already closed by the time I made it back to town but I did about 290 so far on that tank and she's sitting right on a quarter full still so I think this tank will come out really good. Maybe that first tank my ECU was still adjusting timing too in addition to tons of clutch burning stop lights. We will see if it's ultimately worth it considering it's 60c more than the 85 e10 I have been running.
Mine did 20-21 MPG while I lived in West Coast. Ever since I moved to deep south and West TX, the MPG has dropped to 16.6 MPG: Yes, got a lift done but nothing too excessive. City was 12 MPG at best. I then did OEM plug wires, Denso air flow/ratio sensor and O2 sensor and vacuum lines including the vapor feed from charcoal canister with an OEM hose. I think the city MPG has risen to 14 MPG (100% city): Still early to confirm, but that is what I got in last two fill ups.
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