Detroit 6V92 MPG

Topic: Detroit 6V92 MPG (Read 5866 times) previous topic - next topic

Re: Detroit 6V92 MPG

Reply #25 – March 02, 2018, 12:07:25 pm

Cat 3176B ,365HP, 9.3mpg towing or not.....loves the hills

Re: Detroit 6V92 MPG

Reply #26 – March 02, 2018, 12:28:14 pm

On a non winded flat road at 60 mpg towing our solara convertible I get 10mpg. Got over 11 one stretch in Colorado/Nebraska that I posted pictures of.

Bob Rozen(flyte10) got similar results on his 97 u320 after the sane mods.

Boring. Towing at 70 minimum and floored on every hill and revved hard my 12,000 mile average since the mods on the silver leaf is 8.1 mpg, and 97 and 87 psi in the tires

IMO the most noticeable contributions were the resonator and the tires. With Xza-2's and with the throttle off the coach slowed in traffic a noticeable amount.

With the Xza-3+'s you have to use the brakes or retarder much more.

The 3176 engine in a marquis heavier coach towing a Jeep got 8.2 mpg at 65 up and down the hills with the auto jake in use.

Customers loved it as they never moved their feet up or down hill on cruise.

The m11 is no where near that powerful regardless of ratings.

The diesel industry distributors may have turned up their engines and violated the smog law tests long ago and it was rumored that versus fix the older motors over power settings the fix was to turn down the future engines a bit so over years the fleet average emissions would balance out.

Monaco's were turned up for sure and some cats. Sold more coaches, sold more motors

Re: Detroit 6V92 MPG

Reply #27 – March 02, 2018, 01:34:14 pm

Whatever turns one's crank.
Our 1989 GV is comfortable driving at speeds under 60. Over that it gets a little squirrely.
So we drive at our speed.
Our philosophy is to enjoy the journey and then enjoy the destination.
We take living the same way. We know what the destination will be--one of two places

There is so much country we haven't seen yet so we slow down & savor the view. MPG just happens to be a side benefit.

Re: Detroit 6V92 MPG

Reply #28 – March 02, 2018, 01:53:35 pm

Quote from: nitehawk – March 02, 2018, 01:34:14 pm

Our 1989 GV is comfortable driving at speeds under 60. Over that it gets a little squirrely.

I know my friend who has a '89 GV has the same observation. I notice no difference with ours at different speeds having the Torsilastic suspension, newer KONI shocks and wider Michelin tires.

Re: Detroit 6V92 MPG

Reply #29 – March 02, 2018, 07:41:39 pm

Reflecting back on my post ,with driving 65 to 68 being the sweet spot, with a wide body and weight being 33,000 lbs gross.

Re: Detroit 6V92 MPG

Reply #30 – March 02, 2018, 08:50:07 pm

Seeing that this topic has strayed from just the DD6v92, to CATs and other DD's, I will throw out our little Cummins 8.3.
On our almost 9000 mile trip to California and back to FL, we averaged 10.2 mpg with no toad. I had to back out the fuel used by the genset so I used the .7 gal per hour figure that I have seen posted on the forum and the hours on the Gen hour meter. Passed thru the Badlands, Black Hills, Beartooth Mtns to Yellowstone. Then thru the Tetons to Idaho and Oregon, down to Northern Cal then Yosimite.
Las Vegas, Grand Canyon to the 4 corners area before heading thru NM and OK, then back to FL.

Did all of our sightseeing in the Coach...... was happy with the 10 mpg plus.............

Sorry for the long post!

Re: Detroit 6V92 MPG

Reply #31 – March 02, 2018, 09:17:39 pm

In over 100,000 miles, using the Pro-Link 9000, it reads exactly 8.0 mpg. When we bought it at 60K, the Pro-Link read 7.9 mpg so we have gained 0.10 mpg in the last 45,000 miles. We live in the Sierras so it's all Jake and then full throttle and Jake again. Mileage is mostly pulling a 2990 pound RAV4. Going down to San Francisco at 55 mpg, we can get 12 plus but that at a slower speed and flat or downhill. Check my older posts for the photo of the Pro-Link readout.

Any coach with a 4 speed is really penalized with a short final drive. The six speeds should deliver .5 mpg better at least.

Since Detroits are 2 cycles, they only sound like you are abusing them. The max torque is not that far above idle and ours has a fuel cutoff at 2100 rpm. Our old 4107 bus with a non-turbo 8V-71 w/235hp was narrower and lighter and with a VW Rabbit behind, got 10.3 for the worst mpg and on flat ground, it would get just into the teens. It did have a manual gearbox and since it was ex Greyhound, it had a very tall final drive with a top speed of about 90 mph. It got all of it's torque very low and the fuel cutoff was at 1800 rpm. Not even a tachometer was on the dash.

So, the idea of 12 mpg with a 102" 40 foot coach is a fairy tale. Plan on about 8 mpg with a mix of mountain and plains driving with about 65 mph as the normal highway speed. 75 mph will cut it to 6 plus mpg while 55 mph may be a little better. Don't listen to some who boast more on a trip but if the computer readout is looked at over the life of the coach, the mpg will be less. Less with a heavy coach, more with a lighter and narrower U225/240 with a Cummins or CAT. The earlier GVs can average 11 mpg.

Pierce

Re: Detroit 6V92 MPG

Reply #32 – March 02, 2018, 10:37:11 pm

Good info pierce. Here's a run across Nebraska at 65 with no wind. 4K altitude. Charged batteries and zero wind. The 11.9 was at 60. Boring

Actual torque and horsepower curves seem to cross at 70. Lose mpg from wind

Re: Detroit 6V92 MPG

Reply #33 – March 03, 2018, 07:33:22 am

We have even got as low as 4 MPG bucking a 30-35 MPH headwind while going 56 MPH.
Sure don't like headwinds & hills.
We don 't have onboard computers or any type of electronics that record MPG over the life of our coach. (Remember those days?)
So, being that we suffer from voluntary inertia, we only compare what MPG we got on previous trips to our latest fill of fuel.
We have noticed that we are very slowly getting better MPG. Possibly due to the engine getting broke-in? Bought the coach when it had about 62,000 miles on it and now we have almost 84,000 miles on the odometer. Not sure if replacing the stock muffler with a straight pipe affected the MPG much, but it did increase the feeling of more, quicker power.
As I had posted awhile back I found the cruise control wiring problem and fixed that so we do use the cruise control a lot more than we used to, so that likely helps the mileage.
I compare the mileage on each fill-up because any drastic change is, to me, an indicator that something might be going wrong. Being a totally mechanical engine the MPG check is a tool we use to monitor the engine/drive train.

Re: Detroit 6V92 MPG

Reply #34 – January 06, 2020, 09:36:16 pm

On my recent trip over the holidays of about 250 miles I averaged 8.4 mpg towing my little Suzuki Sidekick (2700 lbs) and checked with the Pro-Link Trip Data.

This was running about 62 t0 65 mph and no dash air. Mileage has increased from 8.0 to 8.4 (5%) as Hankook advertised since replacing the old Michelin XZA-1 with the Hankook AL07+ tires. I ran them at 105 psi this time. I like the smooth ride but will try them at 110 psi next time to see if I can gain a little more mpg with the same ride quality.

Bottom line is I like to open the driver's side window just to listen to that DD6v92 rev up and the roar of the Jake. Makes me feel good no matter what the mpg!

Jerry

Re: Detroit 6V92 MPG

Reply #35 – January 06, 2020, 10:12:56 pm

Just finished a trip from Omaha to Waco, TX and back.
No TOAD, tail wind/no wind both ways (EXTREMELY UNUSUAL), no generator run the entire trip.
9.3 MPG

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Re: Detroit 6V92 MPG

Reply #25 – March 02, 2018, 12:07:25 pm

Re: Detroit 6V92 MPG

Reply #26 – March 02, 2018, 12:28:14 pm

Re: Detroit 6V92 MPG

Reply #27 – March 02, 2018, 01:34:14 pm

Re: Detroit 6V92 MPG

Reply #28 – March 02, 2018, 01:53:35 pm

Re: Detroit 6V92 MPG

Reply #29 – March 02, 2018, 07:41:39 pm

Re: Detroit 6V92 MPG

Reply #30 – March 02, 2018, 08:50:07 pm

Re: Detroit 6V92 MPG

Reply #31 – March 02, 2018, 09:17:39 pm

Re: Detroit 6V92 MPG

Reply #32 – March 02, 2018, 10:37:11 pm

Re: Detroit 6V92 MPG

Reply #33 – March 03, 2018, 07:33:22 am

Re: Detroit 6V92 MPG

Reply #34 – January 06, 2020, 09:36:16 pm

Re: Detroit 6V92 MPG

Reply #35 – January 06, 2020, 10:12:56 pm

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