Asheville to Athens,GA

round trip. Plenty of mountains, climbs, decents.

Bridgestone Serenity LRR tires, 38psi all around

To Athens 30MPG trip computer gave avg speed of 60 though it was skewed down from traffic on US HWY 25 and hitting every freaking red light (not literally) but probably 6 or 7 of them.

Athens -> Asheville 28.5MPG got almost all green lights no traffic as hit HWY 25 section at about midnight but this direction has more uphill

Only major tricks were no extreme acceleration and put transmission in Manual mode so car wouldn't shift out of 5th gear on the slightest uphill grade.

5MPH over on Interstate so a bit of time at 70 & 75mph

 

Guess I really need to do pen n paper to see how far off the trip computer is ... Though it definitely reads higher than it did with original Michelins or first gen non-LRR Serenitys.

 

My MID was an average 1 mpg over actual. Sometimes only 0.5, sometimes 1.5. Such meters usually have difficulty with accuracy at the ends of its range, so my guess is that it doesn't measure as much flow at idle as is really being consumed. You see similar behavior from speedometers where below 10 and above 100 they become less accurate.

 

This is of great interest to me because we will soon drive our newly acquired RL on a 2000+ miles cross-country trip, including through the Rockies. We will be loaded pretty heavy, headed back after several months at our second home. Since we only have about 500 miles on it ourselves we don't have a good handle on what to expect as far as mpg.

On a side note, do you have any idea what a pain it can be to buy a car while you're away from your home state? We can't get a proper license plate until we get back, but the state where we bought it several weeks before we return only offers a couple of 3-day trip permits. Hence, our RL is sitting parked until we're ready to head out.

 

Don't bet on 25+ mpg. Make sure your fluids are new, your filter is clean, and your tires are inflated 36+ psi.

 

That's about what I was thinking, about 24-25 mpg should be safe for a rough estimate for budgeting for fuel. We'll be crossing a handful of ranges through the Rockies, along with plenty of flatland driving.

It's killing us to have to leave the RL parked for now, but at least we have another car here so we can use the temp tags for our trip. If we had needed to buy a car because something happened to our old Chrysler we would have been in a real bind. Our old car will stay parked out here for us to use if we decide to fly out for a few months next time around. It still runs well and is worth far more to us than we could ever get from selling it and has new tires, pads and rotors, water pump, timing belt, fairly new transmission, and more. It's showing its age some, but it should still serve well as a car to use around here. Frankly it's even more comfortable for long road trips than the RL, but the RL has a good leg up in several other departments. We tend to invest in maintaining our cars for quite awhile rather than buying another whenever it's practical. As a case in point, perhaps a fairly extreme one even for us, last month we dropped a new engine in a Pontiac Aztek we own that our daughter is using while she takes care of our house while we're away. It cost at least as much or more than the Aztek is worth, but for a few thousand dollars we have a car with a brand-new engine. I used to openly mock people who drive Azteks, but through some weird circumstances we needed a car quick a couple of years ago and my daughter was selling one, so it landed in our laps and we discovered that we really enjoy it. In addition to its utility an driveability and such, I still can't fathom how well it can do on gas mileage. Multiple times I have proven that it can get 32-33 mpg on the highway if I'm willing to slow down to 60-65 mph. That hardly seems possible from such a heavy, high-profile vehicle. I guess we need to see if that still happens with the new engine.

 

FWIW, I drive 350ish miles round trip from Denver to the mountains in southern Colorado every weekend. The MID tells me I get about 26 mpgs (with an average cruising speed of around 70 mph) and I can get about 390 miles out of a full tank with a bit of city driving on either end of the trip. A gas fill at the end of the tank takes about 16 gallons (for those of you who don't want to pull out the calculator, by the math, that's 24 mpg which is withing .5 mpgs of the MID).

 

Agree 25MPG is a good budgeting number. Unless you drive dumb you will most likely budget more than plenty that way. Always better to estimate conservatively.

One thing to do is make a list of states you will be traveling through and the miles in each state. With some planning and help from:

http://www.gasbuddy.com/GB_Price_List.aspx?cntry=USA

You can make sure you don't fill up in one state right before hitting a state where gas is $0.30 a gallon cheaper, or conversely pass through a state looking at gas signs and thinking "Oh we have enough to get to city X in state Y" and find out you just passed up gas that was $0.20 a gallon cheaper.

I really find it helps to (1) Use cruise control and (2) put in Manual to be sure it stays in 5th

The engine really has a lot of torque and unless you hit a seriously steep grade you won't need to pop down to 4th. I've never hit a grade that required anything lower than 4th at 60+

Honestly if I was driving 2000+ miles I'd be more about going a little bit faster to shave off a few hours at the end of the trip than I would be saving gas.

2000 miles at 65MPH is 30.7 hours
At 73MPH it's 27.3

To avoid tickets my rules are 8 over, if every local is passing you speed up a little, and if you're passing *all* the locals then slow down.

 

We plan to take it fairly easy, spreading the driving over about four days. We could do it in three, but plan on a brief stop or two to see people along the way and enjoy the scenery. I often do 5-8 over, but will probably hold it fairly close to the limit on this trip. It's too long a drive to think about going lower just for gas mileage. I already have the Gas Buddy app on my phone and I'm scoping out Costcos and Sam's Clubs near our route. I appreciate the tip for using manual, although I know from experience I'd better not try that around the high-altitude mountain passes.