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RKins · 10-16-2018, 05:25 PM

I like to cruise at 62 on flat lands. When the hills come up I now, based on my smaller diesel, need to manage my speed so that I can average 62. That may mean going 75 on the downhill side to make it up to 62 on the up side.
It is what it is. I don't know if driving secondary roads would change my approach.

Dutch Star Don · 10-16-2018, 05:49 PM

I dial mine in at 62-63mph and find that I'm at a perfect speed out west, where very few trucks pass me and I pass very few trucks.

deryckj · 10-16-2018, 08:33 PM

the road and impede traffic.

strato · 10-17-2018, 08:55 AM

What engine do you have?

stormincb36 · 10-17-2018, 09:22 AM

A diesel mechanic explained to me when I asked about a good speed to drive, that each engine has its "Sweet Spot" and it takes a little trial and error to learn what speed that is. I have learned that for my cummins, 64-65 is optimal. That is where I get the best mpg and the coach seems happy.

Old Scout · 10-17-2018, 10:24 AM

...all good input here but I am more interested in a "comfortable stopping speed"....you will only know what it is if you exceed it some time when you "run into" an emergency situation or you blow a tire ....sorry, but this idea that somehow it is more safe to drive at 75-80MPH is just --well you know!!!!! ....opinions can and do vary of course....so do as you please, just don't involve me and my family in your "bad decisions."

hilgert · 10-17-2018, 02:15 PM

I've never documented them before, but this thread got me thinking about how the wife and I drive. The "rules" below are pretty much what the wife and I follow when driving for comfortable SAFE cruising.

Drive safely for the current road, traffic, weather and day/night conditions. We almost always drive at the speed other large vehicles (truckers) are driving. This is the "smooth flow of traffic" concept, and the objective is to minimize the number of events (passing, etc.) that occur. As an engineer I look at this as our "steady state" condition.
Don't tailgate. We try to stay at least 4-5 seconds behind the person in front of us at highway speeds in order to have reaction time and stopping time (we prefer to not have to slam on the brakes). If someone cuts in front of us we just back off the throttle to regain a safe buffer.
If for some reason we have to drive slower than the majority of traffic (tire issues, low on fuel, etc.), we try to keep out of the way as much as possible. If traffic has to maneuver around us it creates conditions of change for everyone, and change is to be avoided if possible.
Have an overall plan for the day (approximately where you might be stopping for fuel, budget time to arrive at destination during daylight, etc.). Part of our plan is to avoid driving at night. Almost every bad thing that happened (or almost happened) to us when handling a motorhome has occured at night. Plan upcoming fuel stops 100 miles or 90 minutes out...don't wait to find a fuel stop when you are at 1/8 of a tank. And, always have an exit plan before entering any stopping point, especially if you have a towed vehicle. Google maps satellite view is awesome for this...to see where the fuel lanes are and if they present some kind of maneuvering problem.
Have a copilot. The wife and I typically switch driving, and whomever is in the copilot seat owns the plan (see above), does *all* the navigation, fuel monitoring (looking for the next fuel stop) and other logistics. The copilot is allowed to provide "unsolicited observations" about traffic and the pilot's driving performance...over communication is [almost] always better than the opposite. Depending on who's in the pilot seat this may or may not work effectively.
Lastly, for ourselves at least, we don't worry about fuel economy too much. We balance fuel economy against our desire to get where we want to be, and usually we place reducing travel time over fuel economy, but NEVER at the expense of safety.

tropical36 · 10-17-2018, 05:44 PM

Quote:

Originally Posted by Ram-Man

What is a comfortable speed on the interstate that you feel and your coach feels is a good cruising speed on a long distance? I know there are a lot of variables as to each person would have their own comfort level but more interested in knowing what the coach is comfortable with without really having to push it and having to really " drive it ". I hope the question makes sense. Thanks

I pretty much stick with 57 - 58mph, no matter and unless there's a lower speed limit off the interstate somewhere.
This pretty much keeps it in 6th OD over hill and dale and even some hills, that are pretty steep. Once you're in top overdrive, any faster will burn more fuel, unless you have a machine that violates the laws of physics and if so, the boys at MIT would like seeing it....lol
Besides, it not really safe for driving much faster, considering it's size and handling characteristics. After all, the speed limit is for Ferrari's and Vette's, as well, so if a sports car is only safe at 70, for instance, how can a behemoth be safe, at this same speed? Semi's aren't safe for more than 60, truth be known, but then this is all about money, so ..............
In the old days, the speed limit for trucks was posted at 60mph and rightly so.

tropical36 · 10-17-2018, 05:52 PM

Quote:

Originally Posted by RKins

I like to cruise at 62 on flat lands. When the hills come up I now, based on my smaller diesel, need to manage my speed so that I can average 62. That may mean going 75 on the downhill side to make it up to 62 on the up side.
It is what it is. I don't know if driving secondary roads would change my approach.

Whatever works for you, but I really wouldn't want a steering tire blowout at 75mph, let alone with going downhill.

walt_embree · 10-17-2018, 06:27 PM

Quote:

Originally Posted by Old Scout

…..the issue for me is not how fast can I drive but how fast can I STOP?....62-65 is a nice range for me.....In that range, my ISL runs about 1650-1700 RPMs--seems to be a smooth spot for my engine....

Old Scout, NAIL ON THE HEAD! My wife and I chuckled at your great comment. When teaching our [then young] daughters to operate dirt bikes or quads, the very first thing we taught them was “In order to learn to ride fast, you MUST first learn to stop fast!” The same goes for any highway vehicle, but the importance of that concept increases with GVWR.

Thank you for that!

robtou · 10-18-2018, 08:47 PM

We cruise between 62-64 as this is the sweet spot with our Cummings 350. Mileage is anywhere between 8.5 and 10, depending on hills.

Bat4 · 10-19-2018, 03:39 PM

[QUOTE=hilgert;4455171]...As an engineer...

What kind of engineer might you be? A flight engineer, maybe? Your post is almost text-book Cockpit Resource Management, or Crew Resource Management, as I hear it more often referred to these days.

All very good suggestions IMO, and most of which I try to follow. I gotta get my copilot some offsite training; if I tried to teach her myself I think we might need separate beds for awhile.

epj · 10-19-2018, 08:36 PM

60-65 works for me.

Sonic · 10-19-2018, 10:40 PM

Apparently drivers of the rigs that were blowing by me while driving 65 today haven't chimed in.

I swear one guy in a 45' Allegro Bus towing a jeep today was doing close to 85 and tailgating like he was drafting in a NASCAR race before passing each vehicle.
I fear people like that are driving with best case scenarios in mind rather than driving defensively and anticipating what might go wrong, but who knows, the guy could be a skilled professional driver.
I had an 18 wheeler blow a tire in front of me a couple of weeks ago and was glad I had it at 65 and was heeding my driving instructors six second rule.