if you can do 2,850 miles at 55-65 miles per hour I will be monumentally impressed by your patience and frugality

 

Agreed. Mine sounds too mean in the high rpms. I need a rice burner for a dd

 

Good point. That's about 2 days of straight driving. I'm assuming this is a cross country trip, if so there are places with speed limits above 70mph. You'll wanna do 70mph to make up some lost time.

Now I personally get best gas mileage in my XJ at 60mph. I got 23mpg on one trip to visit family. On my way back, I did 65mph and got 20mpg. Both numbers are great in my book.

Don't forget little things like tire pressure and clean air filter. Cruise control made it possible for my good mpg.

 

"Best cruise speed" isn't a function of road speed - it's a function of crankshaft speed. For your 1995 (OBD-I, #7120 head, 42RE trans,) you'll want to look at cruising right around ~2800-3200rpm (a bit higher than RENIX.)

Fortunately, the 6-242 is quite forgiving when it comes to torque peak - a V8 tends to be more "peaky" and wants to cruise in a rather narrower range...

 

100 mph isn't bad, I've been over 100 a couple times in mine

As for the gas mileage, the best I ever got was staying between 70-75 mph, all highway, in 5th gear. Around town, I get the best mileage if I leave it in 4th gear and around 55-60.

 

When they test them for mpg 45mph is what they use so most cars and trucks are built to get the best at 45mph.

 

But does yours have a nasty wobble that you are too lazy to fix lol

 

rpms around 2500 works best for me

 

Can you imagine the DW at 100??!!

 

In my jeep, though mine was an xj....my best mpg was at around 55-57 mph.

 

That sounds about right. Either my overhead console readout was lying when I had it, or I was really seeing my best MPG somewhere between 67-72 MPH.

 

I get best fuel economy below 60mph. Two summers ago I drove 18k miles over 10 weeks and averaged just over 21 mpg for the entire 18k miles, never once did I go over 65 mph, usually cruised at 55 or 60.

 

43MPH

 

Use absolute calculations.

All I know is that when I stopped using overdrive (fifth gear) in my 88, I gained about 3mpg.

And, knowing the ideal cruising crankshaft speed for your engine gives you a cruising speed for each gear range. "Best Cruise" isn't a function of road/ground track speed, it's a function of crankshaft speed. There's a reason that part of being type certified for aircraft (especially piston-driven light aircraft!) involves knowing the output curve for your engine...)

 

gained 3 mpg yesterday by accelerating slowly, tried best to keep under 2500 rpm accelerating, and under 1900 rpm cruising ~60mph

i drive ~400 miles to work and made a conscious effort to get better mpg than avg...

i saved 3 gallons or $15, 3 trips a month = $45 x 12 months = $540 less gas

it was more effort to constantly check my speed/rpm, the ~400 miles probably took an extra 45 mins to travel....

all in all not really worth it, work one extra day a yr to cover the ~$500 in gas and drive relaxed.