I drove my lady's Golf 12 hours to Tucson once and it just siiiiiiiiips gas. It must have been getting 35mpg in the flats with a hair of a tail wind. Soooo fantastic.

Honestly, that I-25 strip down the southern corridor is great for mileage. No strong winds, incredibly flat most of the time. My XJ got 22-24 mpg during that section of road. Just super easy cruising.

 

I should clarify: If you are planning long trips, then miles per tank DOES matter, but you figure it by taking a valid MPG number and multiplying by the tank capacity.

NEVER measure fuel economy by miles per tank. It's not anything resembling an accurate, repeatable measurement.

 

I fill up at the 1/8 mark on mine and I'm always at 250ish miles.

I calculate mine by dividing how many miles I drove by how many gallons I filled up with. I always reset the trip odometer at fill up, and I always fill up til the pump clicks off. So last time I went 246 miles, divided by the 14.6 gallons I pumped = 16.8 mpg

 

And that, ladies, is the only correct way to do it.

(And if you aren't tracking it, you are missing important information about how your engine is behaving.)

If you have an Android device, look into aCar. It is the most well-done piece of software I have ever used.

 

2001 with 200+ gets 19-20 on highway taking it easy.

 

I have a 98 xj 2D and I get between 16 and 18 normally 50% in town/50% on highway. It’s also totally stock

 

it's an engine designed in the 60's. I think I get about 15.

 

If you're talking about the 4.0, then I dunno what to say about just how wrong you are with your claim that it was designed in the 60's... Sure, it shares a few features with its ancestors, like the fact that it has 6 cylinders, that it runs on gasoline. Oh, it also has spark plugs, too. For real though, the AMC inline 6 family was a lot of iterative design, but over time that results in a new product. The 4.0L is by no means a modern engine, and outside of its engine management system and fuel injection wasn't super advanced, but it is NOT as inefficient as something you'd find in the 60's. Most things central to the engine actually running are at LEAST a little different owing to the introduction of port fuel injection, from engine structure to cam profile, and they almost doubled the number of bolts for the valve cover, among many other things. AMC did reach into the parts bin as they usually did, so where they could they did reuse parts - but as far as I know there are very very few things you can interchange between a 4.0 and any of the legacy AMC 6's from the 258 back. The biggest thing of note is that the 4.0 is compatible with a large number of older AMC transmissions due to AMC's adherence to keeping the same bellhousing bolt patterns for so many of their designs.

On the topic of gas mileage, I get 14-20 based on where I am, what I'm doing, and how heavy my foot is. I had an AMC 360 and an AMC 258 sitting in the back for a 3 hour highway drive and got 18. That's like 1200 extra pounds!

 

you're taking what I said a bit to literal my guy. What if I said you can put the 258 crank in the 4.0 , we meet in the middle , lets it was designed in the 70's? It's an old *** engine and it is clearly was built around very old design principles. I never said it was a bad engine, it's an old engine. AMC was building and revising this setup for decades. start with a 232 in the 60's, stretch the block and a few bits to create the 258, then do some more edits and boom a 242 4.0. The 4.0 had similar or better economy and power numbers compared to its competitors in the 80's but dang dude they made the 4.0 til like 07. Everyone else was wayyy passed it by that time.

Bob Sheaves himself said this-
Saying it was designed in the 60's is a good one liner to say it's literally a modified 199. please correct me some more.

 

oops

 

"Designed in the 60s" is accurate. Yes, there were refinements, but the basic design was there.

https://www.4wd.com/article/content....r-Motor-Engine

 

Guess which engine this is, guess when it was made, guess what it looks like.

 

1990 4 liter renix 33 inch x 12.5 mt tires. 4.11 gear, added weight of winch, camping gear, etc..

15 to 17 mpg on flat highway, speed dependant. 15 mpg if my foot is in it a bit, 70 to 75 mph. 17 mpg if I do 65 mph or so.

offroad, usually 6 to 8 mpg, terrain dependent.

 

I like the color. I know I've seen it before, but I can't place it.

 

First thing that popped into my head was Pontiac engine blue.