Community Forums

BOBCO · 08-11-2014, 04:50 PM

Going on first big trip in a couple of weeks from SW CO to Glacier National Park. What speed do people generally drive? Do you drive faster on the interstates?

halfwright · 08-11-2014, 05:06 PM

I drive 58-60 most of the time. That is with an 2002 F250 Superduty 7.3 liter diesel pulling a 36 ft Montana 5th wheel. That is 1950 RPM in overdrive. That gives me 11-12 MPG. It is the air drag that hurts more than the weight.

jimcumminsw · 08-11-2014, 05:39 PM

Your tires on the trailer are speed rated for 65mph if they are st tires. Now I try to stay in the RH lane and drive 60 to 65 mph with my trailer and truck. I have the attitude I will get there when I get there,65 mph is fast enough.

Jim W

BFlinn181 · 08-11-2014, 06:30 PM

You will see a dramatic drop in mpg if you try to push faster than 60-65 mph. The amount of air drag is an exponential increase. Slow down and enjoy the scenery, remember, you're on vacation!

longshot · 08-11-2014, 06:45 PM

I try to stay 65 or below but if I get on a super smooth highway I'll find myself doing 75 in no time

glennwest · 08-11-2014, 06:47 PM

I'm not on vacation towing. I am towing to next job. Sometimes I have to get there quickly. We are full time also. I do not have ST tires though. XPS Michelins

Boogie_ · 08-11-2014, 07:15 PM

60-65 mph for me.

Best thing about it is that it's like you've got the whole interstate to yourself.

Rarely have to pass anything, no stress, cute thing next to me talking her head off.

...good times.

mo5er · 08-11-2014, 07:30 PM

Safe speed on the country roads, 60-65 on the interstates. We are retired and enjoying the ride!

pitcrew18 · 08-11-2014, 07:37 PM

Normally 65 to 70 max highway and posted speed on secondary roads.

sknight · 08-11-2014, 07:45 PM

I'll go the speed limit up to 65, but the world isn't likely to end if you ramp it up to 75 to get around a slower truck then move back over. One of my great peeves, two trucks, climbing a hill, one running 60, the other running 60.5 and trying to pass the first truck over the course of five miles. Call it dangerous, but when I go to pass someone, I get it done and move back over. If I can't get it done, I'll wait until a hole in traffic opens up.

Back with my TT I got 10.5MPG at 65, tried 70 for 100 miles and it dropped to 7.5MPG. My truck runs 1950ish at 65 and 2050ish at 70. There's a change in the engine programming apparently as the engine even sounds different.

mahdi · 08-11-2014, 08:04 PM

Most RV tires are sold as SD and those are rated for maximum 65 MPH. LT tires can go up to 75. I agree with SKnight when overtaking a slow truck you can speed up and then come back. On flat highways we do 11-12 MPG in a Cummins diesel. Some places like west Texas on I 10 you can go faster but at 80 MPH the truck will do 9.5 MPG. Now that I have had 3 blow-ups in 24 hours, I am sticking to 65 MPH. Slow down and enjoy your trip.

Tony Lee · 08-11-2014, 08:27 PM

It is your first major trip and what speed others drive at isn't relevant to what you do. Slower is cheaper, allows you a bit more of a chance to see the scenery, and is easier on your rig as well.

Perceptions vary - some here say slow down to 65 whereas I would regard that as speeding up.

Larry · 08-11-2014, 08:39 PM

The best speed is the one you feel comfortable driving. For years before I retired it wasn't unusual to be running at least 70 or more, however now I normally keep around 68.

road dogs · 08-11-2014, 08:45 PM

I drive 63-65, that seems to be a sweet spot for mpg and being able to stop if traffic jams up suddenly. I'll sometimes kick it up to 70 at night if it's within the limit and the weather is cool.