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NightFlyer
09-04-2013, 12:50 AM
Just wondering what kind of mileage other owners are experiencing with their D's.

On my last trip of about 100 miles, 90% highway at 60mph average, I experienced about 26 MPG with the 5-speed manual.

So, what kind of mileage are you seeing from your D? Post your results here!

Josh
09-04-2013, 01:18 AM
Well my car has travelled about 3500km without burning a drop of fuel. I think that is somewhere around infinity MPG

Bitsyncmaster
09-04-2013, 05:17 AM
Last I checked, 28 to 29 MPG on highway driving. Manual transmission.

Greasy DeLorean Mechanic
09-04-2013, 08:30 AM
The only drive I make regularly is to/from DC (I'll be up there next week). Takes about 8 gallons to drive 180 miles through the state of North Carolina. Includes stop & go traffic through Fayetteville, then 128 miles at 75-80 MPH -- average 23 MPG. As long as I buy 8-9 gallons as soon as I cross over the border I know everything's normal.

If I could keep my speed closer to 60 MPH I'm sure I would see an increase in MPG, but travel time is more important to me than a gallon or two of gas (an extra 10 MPH saves me slightly more than one hour over the whole trip).

Bill Robertson
#5939

Greasy DeLorean Mechanic
09-04-2013, 08:43 AM
FWIW: in 1981 Road & Track tested a factory new DeLorean at 19.5 MPG (Gold Portfolio p. 85) and Car & Driver tested one at 18 MPG (Gold Portfolio p. 93).

Bill Robertson
#5939

Duplicate Account
09-04-2013, 09:01 AM
I'm sure I don't have to tell you that the Virginia State Troopers are out in full force right now. They inflate the speed so they can then say they reduced it when they hand you the ticket. Safe travels, Bill

Greasy DeLorean Mechanic
09-04-2013, 09:23 AM
Trust me: I give the Virginia State Police a wide berth. Unlike North Carolina, which is running a 100 Trooper deficit and doesn't have any money to hire replacements, Virginia seems to be able to support a state car at every crossover. Speed limits have been raised to 70 on either side of Richmond, so I'm OK at 75. There's always a state policeman at the border to catch people ripping across at 80 plus.

Bill Robertson
#5939

stevedmc
09-04-2013, 09:40 AM
My car is carbureted and has a slightly upgraded ignition.

I've gotten as high as 28 mpg but that is with me driving no faster than 60 mph and with a tank of real gas.

Depending on the quality of the gas I usually get 22 to 25 mpg on long road trips. This is with me driving between 75 and 80 mph.

Greasy DeLorean Mechanic
09-04-2013, 11:16 AM
A common misconception is that the old 55 MPH national speed limit was imposed for safety. Nothing could be further from the truth -- it was imposed for fuel economy. Bottom line: if you drive at the new 70 MPH norm, MPG will go down (all other factors equal) -- period. The question each driver must answer for him/herself: is decreased fuel economy worth decreased travel time?

I do lose patience with arguments that carburetion will throw your fuel economy in the basement. A technical argument can be made that active engine management, even as rudimentary as North American K-Jet, delivers "better fuel economy", but the real world difference is probably less than 1% or so. It's like saying a Double Quarter Pounder With Cheese has fewer calories than a Big Mac. Listening to pontificators and prevaricators you would think a carburetor throws your car into the single digits.

Bill Robertson
#5939

Bitsyncmaster
09-04-2013, 11:51 AM
The best way to get max MPG is don't touch the brakes (unless you have to). That means you start slowing down way before you need to stop at intersections, don't follow too close, etc. It has more effect on city driving but even highway can add up. Get the car shifted into high gear ASAP (shift at low RPM). On my daily driver Malibu I have learned to keep the overdrive and torque converter locked with very easy accelerator movement and staying above 42 MPH. Also the Malibu has a great MPG readout that helps you learn tricks to improve.

NightFlyer
09-04-2013, 12:14 PM
The best way to get max MPG is don't touch the brakes (unless you have to). That means you start slowing down way before you need to stop at intersections, don't follow too close, etc. It has more effect on city driving but even highway can add up. Get the car shifted into high gear ASAP (shift at low RPM). On my daily driver Malibu I have learned to keep the overdrive and torque converter locked with very easy accelerator movement and staying above 42 MPH. Also the Malibu has a great MPG readout that helps you learn tricks to improve.

Dave, you're getting some great numbers. When approaching a stop, do you downshift or simply shift into neutral?

I'm currently shifting around 3,000-3,200 RPM. Perhaps if I lowered that to 2,300-2,500 RPM, I'd approach the 30 MPG mark as you... what do you think?

NightFlyer
09-04-2013, 12:18 PM
My car is carbureted and has a slightly upgraded ignition.

I've gotten as high as 28 mpg but that is with me driving no faster than 60 mph and with a tank of real gas.

Depending on the quality of the gas I usually get 22 to 25 mpg on long road trips. This is with me driving between 75 and 80 mph.

I too have noticed about a 2-3 MPG difference in using ethanol free gas vs the blended stuff. I think I'm going to buy three 5 gallon containers and stock a tank of ethanol free at the house for the car, as the closest station offering it is about an 80 mile round-trip drive away and kinda out-of-my-way.

NightFlyer
09-04-2013, 12:24 PM
A common misconception is that the old 55 MPH national speed limit was imposed for safety. Nothing could be further from the truth -- it was imposed for fuel economy. Bottom line: if you drive at the new 70 MPH norm, MPG will go down (all other factors equal) -- period. The question each driver must answer for him/herself: is decreased fuel economy worth decreased travel time?

I do lose patience with arguments that carburetion will throw your fuel economy in the basement. A technical argument can be made that active engine management, even as rudimentary as North American K-Jet, delivers "better fuel economy", but the real world difference is probably less than 1% or so. It's like saying a Double Quarter Pounder With Cheese has fewer calories than a Big Mac. Listening to pontificators and prevaricators you would think a carburetor throws your car into the single digits.

Bill Robertson
#5939

I'm 100% with you on everything here.

When I moved to Lansing, MI, several years ago, the speed limit on I-496 (which unlike most triple digit interstates is the straight-through and not the bypass) was reduced to 55 MPH through town, supposedly for safety reasons. 2 or 3 years ago, they increased it to 70 MPH, keeping the limit consistent on the entire length of I-496. I remember reading an article showing that after the first year and half of the increased limit through town, accidents/fatalities actually decreased. No better proof.

Bitsyncmaster
09-04-2013, 01:56 PM
Dave, you're getting some great numbers. When approaching a stop, do you downshift or simply shift into neutral?

I'm currently shifting around 3,000-3,200 RPM. Perhaps if I lowered that to 2,300-2,500 RPM, I'd approach the 30 MPG mark as you... what do you think?

I usually downshift when coming to a stop but that probably hurts milage. I shift about 2,500 unless I need to get quick acceleration. But there are times when I would shift at lower RPM.

It's funny how some people drive so different. One of my idle ECU users would not down shift until getting to around 1,000 RPM. That made me change the ECU software a little.

NightFlyer
09-04-2013, 10:44 PM
I usually downshift when coming to a stop but that probably hurts milage. I shift about 2,500 unless I need to get quick acceleration. But there are times when I would shift at lower RPM.

It's funny how some people drive so different. One of my idle ECU users would not down shift until getting to around 1,000 RPM. That made me change the ECU software a little.

Indeed it is. I'll try shifting at 2,500 and see if that pushes me to the 30 MPG mark.

Thanks Dave!

NightFlyer
09-09-2013, 09:58 PM
OK, so this weekend, I started shifting between 2,200-2,500 RPM and shifted into neutral when approaching stops as opposed to down shifting as I normally would. A/C off (currently non-operable in my car), drop glass down, 10% ethanol blended fuel, average speed 54 MPH on a mostly highway 80 mile round-trip with only a light breeze (no wind).

Average fuel economy realized: 31.6 MPG!!!

Greasy DeLorean Mechanic
03-29-2014, 12:29 PM
Click & Clack's column in today's paper was all about speed's effect on fuel economy. They referenced the following study, which admittedly is truck based, but the principle is the same: fuel consumption at 75 MPH is higher than at 55 MPH, no matter the vehicle -- period: http://www.bridgestonetrucktires.com/us_eng/real/magazines/ra_special-edit_4/ra_special4_fuel-speed.asp

FWIW: Note travel times at the bottom of the page: 55 MPH (in a tractor trailer) increases travel time 36% with a 39% fuel consumption penalty -- pretty much a wash if you value time as much as money.

Use those numbers to do some DeLorean math:
- 500 miles at 30 MPG = 16.66 gallons @ $3.35 = $55.81. 39% more fuel = $77.58 ($21.77 more).
- 500 miles at 55 MPH = 9.09 hours. 500 miles at 75 MPH = 6.67 hours (2.42 hours less).

The question each driver must answer for him or herself: is it worth (approximately) $21.77 to save (approximately) 2.42 hours travel time? (DeLoreans don't have screaming children in the back seat...).

Bill Robertson
#5939

Boo
03-29-2014, 01:44 PM
As I mentioned before in the carb without carbs thread:


I try to make my gas mileage as low as possible. Driving at high RPMs and WOT. Too much fun to waste gas so I waste it.

stevedmc
03-29-2014, 02:23 PM
Rather than focus on miles per gallon, think about gallons per hour...


https://www.youtube.com/watch?v=G7nRRykiOGc

tom kish vin.4357
03-29-2014, 02:31 PM
Great!!! finally a real video of brother Bill an one of his custom carbs!! thanks Steve!!!