Fuel Mileage

**MidwestCamper** · 08-06-2018, 05:16 PM

Originally Posted by Cate&Rob

Hi Rob - I am still on a "first name basis" with the 46 year old triple carbureted straight 6 engines for my boat . . . so, I guess I better keep my "classic" tools

.

Rob

Now that is really cool stuff. We need some history in what that boat that is going in.

**MidwestCamper** · 08-06-2018, 05:28 PM

Originally Posted by Cate&Rob

Jim - Thank you for your insight into this. I have been doing some "homework" and am totally amazed at the engine information available through the OBD connection -> bluetooth -> iPad . . . for an insignificant amount of money! The main software suppliers seem to be DashCommand and Torque Pro. Both work from the same bluetooth connection and are really affordable . . . if you have an iPad or an iPhone . I am going to give this a try!

I guess I don't need my feeler gauges, dwell meter and timing light anymore

. The first turbo charged engine that I ever "messed with" was a small aluminum V8 . . . that came out of a 1963 Buick! (It wasn't in the Buick, when it got to me

)

Rob

Rob,
I did some reading on the 215 and it has a great history. I'm 61 and missed this one but having it in the TR8, land rover and at Indy is awesome. I worked as a technician back then and wrenched on some really old stuff like yourself but my engineering started with closed loop systems. The simplicity in those old systems is the fact that you could sit on the fender well under the hood of your truck. That was so nice!

**Cate&Rob** · 08-06-2018, 05:52 PM

Originally Posted by MidwestCamper

Rob,
I did some reading on the 215 and it has a great history. I'm 61 and missed this one but having it in the TR8, land rover and at Indy is awesome. I worked as a technician back then and wrenched on some really old stuff like yourself but my engineering started with closed loop systems. The simplicity in those old systems is the fact that you could sit on the fender well under the hood of your truck was so nice.

Jim - The Buick 215 cu in aluminum block engine was so far ahead of its time. Cast in place steel cylinder liners was one of the key inventions that made it work. Then, GM decided there was no future in small engines (remember that this was the muscle car era) so they sold the aluminum V8 and iron V6 designs and tools to Rover. A few years later the gas crisis and emission regulations appeared and GM bought back the iron V6 . . . but Rover kept the aluminum V8.

I know . . . this particular moderator is worse at keeping these threads on track than most of the members . . . guilty as charged

.

Rob

**MidwestCamper** · 08-06-2018, 05:52 PM

Originally Posted by VinceB

When I got back from South Dakota and checked my mileage, I was pleasantly surprised to see 11.8 mpg with my setup. I just got back from a short trip to Michigan and it was right around 12 mpg. I used the trip calculation from the TV and also did it manually to be sure. I was surprised because mpg. I keep my speed right at 62 mph as that seems to be my sweet spot. I’m happy with my results.

Vince,
This is a great way in doing this. I found that I can gain a little fuel economy on my 5.3 liter by running at 67mph on a calm day running in 5th gear/6spd. The reason is the engine is running at a slightly higher torque value, is not yet being enriched, and is slightly more unthrottled. This is all a balancing act in finding the most efficient speed. But I do not like running up there and will usually run 60-65. 60 on windy days.

**DandMZ** · 08-08-2018, 06:19 AM

My 2017 F250 CCSB with a 6.2 and 3:73 gets 12mpg unloaded suburban driving (24 stoplights in my back and fourth commute). Took our Imagine 2970 on its maiden voyage last week and recorded just over 10mpg.

**Cate&Rob** · 08-08-2018, 07:35 AM

Originally Posted by MidwestCamper

Now that is really cool stuff. We need some history in what that boat that is going in.

Jim (MidwestCamper) - See this post in the "Hobbies" section for the boat that goes with that engine

.
https://www.mygrandrv.com/fo...514#post180514

Rob

**jmbopp** · 08-12-2018, 07:20 PM

I get between 8 and 10.5MPG on my '12 EB and Imagine 2650. Variables are regular vs premium fuel, if I have a canoe on top of the truck or not, and if there's a headwind. I figure the canoe adds 1/2 to 1 MPG increase and premium fuel keeps the tranny from hunting on mild grades. I think the computer senses knocking with 87 octane and downshifts to increase the RPM's to compensate. My theory only.

**MidwestCamper** · 08-12-2018, 07:34 PM

Just returned from a 642 mile round trip to Salt Fork State Park in southern Ohio. Was making 11.0 mpg @63 mph until hitting the Appalachian area where the mileage settled in a 10.6 upon parking at our site. On the return trip, we traveling in a slight head wind and ended up at a total trip average at 10.5 mpg. 63 MPH results in a cruising RPM at 2000 with 2700 RPM on downshifts on grades.

Empty: 19-20 mixed driving, 22-24 hwy. 89 Octane fuel

**GeoffnCheri** · 08-12-2018, 07:53 PM

2011 F-250 6.7L CC Average 18.5 mpg empty on hwy, 16.6 empty in town. 10.5 towing the 5ver loaded

**MidwestCamper** · 08-13-2018, 06:06 PM

Originally Posted by jmbopp

I get between 8 and 10.5MPG on my '12 EB and Imagine 2650. Variables are regular vs premium fuel, if I have a canoe on top of the truck or not, and if there's a headwind. I figure the canoe adds 1/2 to 1 MPG increase and premium fuel keeps the tranny from hunting on mild grades. I think the computer senses knocking with 87 octane and downshifts to increase the RPM's to compensate. My theory only.

jmbopp,
Your engine (or any other) through knock will reduce spark long term until it no longer detects knock. As a result, the delivered torque is reduced and the transmission will recognize this and will force the downshift. Otherwise, additional heat will be produced which can result in further knock and spark retard. This is normal operation. You can experiment and run premium and check fuel economy and then under the same ambient conditions run regular fuel. Check this against the cost of each fuel and you may be surprised that the premium fuel may save you some cash. E85 is another one that produces much more torque but burns much more fuel to maintain the proper air/fuel ratio. If you can find E85 that is at 70% or below the current cost of gasoline, you will save money by burning E85. I've never seen it that cheap so I do not buy it.