Redneck DoD

[L31MaxExpress]

I never had a GenIV with DoD, but the GenV DoD does work (assuming the instant MPG display isn't programmed to lie). It's a lot more effective in my Corvette than it is in the Yukon though. The C8 can stay in V4 for hours, but the Yukon being a big heavy brick never stays in for long.

I have never seen it make a difference in GM or Dodge vehicles. I owned one vehicle with it and refuse to own any others with it. My Hemi Ram actually did better on fuel with it disabled. Then I put a very mild 212/212 @ 0.050 cam into it and eliminated the system entirely. With the cam and 4.56 gears I was getting 2-3 mpg better than the truck managed stock with the MDS enabled and 3.55 gear. Years ago I had a 1995 LT1/6spd Camaro. Even with a LT4 conversion package with the Hotcam, it routinely managed better than 30 mpg on highway trips which at the time impressed me for a 400 hp V8.

 

[0xDEADBEEF]

I have never seen it make a difference in GM or Dodge vehicles. I owned one vehicle with it and refuse to own any others with it. My Hemi Ram actually did better on fuel with it disabled. Then I put a very mild 212/212 @ 0.050 cam into it and eliminated the system entirely. With the cam and 4.56 gears I was getting 2-3 mpg better than the truck managed stock with the MDS enabled and 3.55 gear. Years ago I had a 1995 LT1/6spd Camaro. Even with a LT4 conversion package with the Hotcam, it routinely managed better than 30 mpg on highway trips which at the time impressed me for a 400 hp V8.

On trucks and SUVs it's probably miniscule over the lifetime of the vehicle. The only time it will stay in V4 is downhill or slower speed. One the C8 it definitely works. I easily got 28 MPG on the highway with it enabled and low 20s with it disabled on the trip back from Bowling Green during engine break-in, which was the last time cared about it.

My stock LS1 firechicken would get 30 mpg in 6th gear no problem. After all the mods it was more like 24 mpg, but still pretty good. The firechicken was probably lighter and had less frontal area than my C8 though.

 

[95burban]

Firm believer that it’s better to have to much HP/TQ than not enough. Let’s make an engine work less. Basically referring to these newer trucks with baby turbo engines.

 

[L31MaxExpress]

On trucks and SUVs it's probably miniscule over the lifetime of the vehicle. The only time it will stay in V4 is downhill or slower speed. One the C8 it definitely works. I easily got 28 MPG on the highway with it enabled and low 20s with it disabled on the trip back from Bowling Green during engine break-in, which was the last time cared about it.

My stock LS1 firechicken would get 30 mpg in 6th gear no problem. After all the mods it was more like 24 mpg, but still pretty good. The firechicken was probably lighter and had less frontal area than my C8 though.

My 2011 M56S would get 28+ on road trips at a sane speed. 22-24 running 90+. It was a V8 all the time, but turned extremely low rpm even at 80+ mph. You had to be running better than 90 mph to get over 2,000 rpm. It had a 7 spd and a 2.62 ring and pinon but was a 4,200 lbs sedan.

 

[0xDEADBEEF]

My 2011 M56S would get 28+ on road trips at a sane speed. 22-24 running 90+. It was a V8 all the time, but turned extremely low rpm even at 80+ mph. You had to be running better than 90 mph to get over 2,000 rpm. It had a 7 spd and a 2.62 ring and pinon but was a 4,200 lbs sedan.

The C8 gets 28 mpg, has a 450+ mile range, AND runs low 11s in the 1/4. Pretty impressive, IMO. I don't really care about the MPG though.

 

[L31MaxExpress]

The C8 gets 28 mpg, has a 450+ mile range, AND runs low 11s in the 1/4. Pretty impressive, IMO. I don't really care about the MPG though.

Thats moving for sure. Mine went high 12s stock, low 12s with intake mods, custom 2.5" dual exhaust and tune with nearly 100K miles on it, moving pretty good for a luxury sports sedan in 2011. On long trips, 500 miles was about when the low-fuel indication would come on and I never put more than 18 gallons in the 20 gallon tank. I loved the way that car ran, drove, handled, rode, and all the cool featurea it had. Made for an ultra comfortable, spirited vehicle to daily drive and road trip even if it was not the fastest thing on the road then. Just happened to get exceptional mileage if you set the cruise at 75-80 mph and stayed out of the skinny pedal. It was hard to do especially after the exhaust went on because I loved the way it sounded, like a modern 5.0L Mustang on steroids because of the added displacement.

 

[Schurkey]

I had this thought about wiring a couple switches. One grounds out Injectors 1, 4, 6, and 7. The other grounds out 8, 3, 5, and 2.

If you "ground out" the injectors, does the excessive current flow then pop the drivers in the computer?

I'm thinking that if you HAVE to do this, you want to OPEN the circuit, not ground it.

The goal is to increase my gas mileage on the highway.

Drive slower...

my #3 injector has been consistently misfiring

...and/or fix the engine so it runs properly. Assure all "tune-up" items are in good condition. Inflate your tires to proper pressure. Make sure the brakes don't drag. Put synthetic lube in the oil pan, differentials, etc. for reduced parasitic losses.

So besides my computer throwing codes for constant misfires, can anyone see any reason not to do this for those many hours cruising at highway speeds?

Yes.

Not so sure why keeping the valves closed is so important. It is not sucking mixture in, just atmosphere. Then it's compressing and sparking like normal, and blowing out the exhaust.

Blowing "atmosphere" (air) into the exhaust will screw-up the O2 sensor readings, leading to a false-lean condition. The computer compensates by going into "rich command" where it's adding more fuel to the cylinders that do run.

This is a REALLY BAD idea. You wash the oil off the cylinder walls with a too-rich mixture, and bore wear, ring wear, and maybe piston scuffing increases.

 

[0xDEADBEEF]

Thats moving for sure. Mine went high 12s stock, low 12s with intake mods, custom 2.5" dual exhaust and tune with nearly 100K miles on it, moving pretty good for a luxury sports sedan in 2011. On long trips, 500 miles was about when the low-fuel indication would come on and I never put more than 18 gallons in the 20 gallon tank. I loved the way that car rand, drove, handled and all the cool featurea it had. Made for an ultra comfortable, spirited vehicle to daily drive and road trip even if it was not the fastest thing on the road then. Just happened to get exceptional mileage if you set the cruise at 75-80 mph and stayed out of the skinny pedal. It was hard to do especially after the exhaust went on because I loved the way it sounded, like a modern 5.0L Mustang on steroids because of the added displacement.

It learns how you drive to display estimated range. At first mine would say over 500 miles on a full tank. After my first track day it said 75 miles. LOL. ~3.5 MPG.

 

[0xDEADBEEF]

Anyways, my point being that if worked in the trucks as well as the vettes I think people would appreciate it more. That and if it didn't have a tendency for the lifters to fail.

 

[L31MaxExpress]

It learns how you drive to display estimated range. At first mine would say over 500 miles on a full tank. After my first track day it said 75 miles. LOL. ~3.5 MPG.

I believe that. The instant economy PID in the Scanner app on my Android head unit in my 1997 Express shows 2.xx mpg climbing long, steep grades with a heavy trailer.