How fast does everyone cruise on the highway in their truck?

[2badgn]

Just ranting here- I have a restored 84 GMC 3500 Pickup with 350 engine.

I live in NY and after the hurricane, I was desperately looking for a generator- took an hour ride to Chester, NY ---and I was purring around 70-75 round trip.

The place didnt have the generator but i found one on the way home at my local Home Depot. After putting the generator together, I went to get some gas for it but all gas stations had no gas EXCEPT for 1 Hess station.

I ran out of gas with my truck at a Chase ATM. - theres a first time for everything.

Fuel gauge doesnt work----its a new tank and new sending unit.

Going to change the gauge next.--
Just curious- how fast do u guys/girls cruise in your pickup on highway?
And my truck even has a Tonneau cover .

[INSIDIOUS '86]

I cruze at 60 at 3000rpm in my no overdrive truck with 373 gears. I usually go 70 though. I used to have a 305/700r4 combo and 2.73 gears. With the converter locked I went about 1200rpm at 70mph lol it was great
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[oldtek]

I cruise my 6.2 burb (th400 3.73s) around 70 if on a busy freeway. 60 on emptier highways to conserve fuel.

Hope you and yours are doing well following the storm.

[2badgn]

My truck has a 350 with new Rochester Quadrajet and 4.11 gears .
That thing can haul and move.
But i have learned my lesson about how badly it consumes fuel at 75 mph.
Next time I will be just be cruising around 65 until I get that damn fuel gauge fixed!

We r okay - I am in Yonkers- lost power for 3 days- but thats nothing compare to the people in New Jersey, Long island, Staten Island and lower Manhattan. God help us all.

[kylep]

on a short trip i will go 60 to 65. but anything longer than 15 minutes i will only go 55-60 in notice a bad change in mpg when i go above 60.

[zaccaglin]

Did 90 (Accourding to GPS) in my 6.2l quit a few times. Only issue I've had besides mullahs was I froze up my ac compressor one day when it was about 102 out coming back from pick n pull.
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[EasySteve]

Speed limit around here is 70 on the freeway, but we all know how squares are.
I cruise at 60-65 (depending on traffic) pulling 2000-2100 rpm.
454, 2.73s, and an sm465.

[INSIDIOUS '86]

Statistically past 55mph most vehicles optimum mpg drops off and the speed vs fuel burned starts to become vastly more skewed
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[EasySteve]

Originally Posted by INSIDIOUS '86

Statistically past 55mph most vehicles optimum mpg drops off and the speed vs fuel burned starts to become vastly more skewed
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So...statistically...since we dont fall under modern vehicle statistics, we shouldnt be going faster than 35 if we want to save gas. Hahaha.

[Keith Seymore]

Originally Posted by EasySteve

So...statistically...since we dont fall under modern vehicle statistics, we shouldnt be going faster than 35 if we want to save gas. Hahaha.

No - seriously - drag is affected by the square of the velocity (not just the velocity alone) - so the drop in fuel economy is exponential rather than linear.

That's for all vehicles, not just those in the shape of a brick.

K

[slugish]

Originally Posted by Keith Seymore

No - seriously - drag is affected by the square of the velocity (not just the velocity alone) - so the drop in fuel economy is exponential rather than linear.

That's for all vehicles, not just those in the shape of a brick.

K

Lost me on this one Keith. Any explanation for dummies

[EasySteve]

Originally Posted by slugish

Lost me on this one Keith. Any explanation for dummies

He means..the faster you go, the more the rate of fuel consumption will increase. So lets say you go 80 and get 15 mpg, then 90 could be 13, but then 100 could be like 8, because the force against the vehicle is increasing very quickly. If that helps at all...

Linear would be 80mph=15mpg, 90mph=13mpg, 100mph= 11mpg, and so on.

[Keith Seymore]

Originally Posted by slugish

Lost me on this one Keith. Any explanation for dummies

Sorry bout that!

The formula for drag is:



and the problem is that "v" - which is not just a "v" but is "v squared".

Graphically it looks like this:



and you can see that instead of increasing in a linear, or straight line fashion, the drag is increasing faster than you would expect for an increase in speed.

K

[EasySteve]

When getting on the freeway my speedo is pegged at 85, but it is off by a good percentage. Truck hasnt been above 80 in 17 years...time to break that with my 454?

[Skunksmash]

I got 2.73's in the rear end of my 87. So I cruise at about 65/70. Beyond that the aerodynamics take over and the air starts pushing back so the RPMs have to go up to the point that its not actually worth it to go any faster. You're just wasting gas. My RPM's at 70 are about 2200. At 65 they're about 2000, 2050, somewhere in there.

My 94 GT mustang also has 2.73's in the rear end, and it doesn't hit 2100 RPM until 80. 85 MPH is about 2200 in that car. That's why I think I'll just do other speed parts and Keep the 2.73's. I like low highway RPMs. Same for the truck.

[bigd65]

I just ride, I don't pay attention, not fast or slow, just ride !!!!
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[gchemist]

70 MPH at 1950 RPMs, without head wind, 18.5 MPG was the best average. I can probably hit 20 at 65 MPH.

Texas fastest road is 85 MPH for 41 miles!! Two buddies and I are taking a trip to San Antonio from Austin this weekend. BADBOW is going to do the full length at 85 MPH round trip. We'll have to use GPS since the needle is broken and speedo pegs out at 85!!
Wait for pics!! Hopefully, I can grab a few quick videos!!

[Keith Seymore]

Originally Posted by 2badgn

How fast does everyone cruise on the highway in their truck?

By the way, to answer the question, 70 mph (indicated) for me, which seems to be about 67 actual.

4.3L V6, MY6 overdrive trans, 3.73 axle.

I'm the slowest thing on the road around here -

K

[SSC's76]

I usually cruise whatever the speed limit is. my truck has 3.08s in it now I hate them but on the highway it sure makes a difference.


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[Firebirdjones]

In my 79 with 3.73's and a 29" tire (no overdrive) I like to keep the engine around 2800 on the highway, which is about 67 mph. Sometimes I cruise 70 mph at close to 3,000 if I feel the need but not often. Usually just put it on 65 and hit the cruise control button.
When the gear vendor goes in it will drop the rpm down 700-800, at which point I can bring the cruise speed up to the limit here (75 mph) and still turn less rpm than I did at 65 without the overdrive engaged.

In my Blazer I run an overdrive with 3.73's and cruise that at anywhere between 65-75 mph depending on whether I'm in a hurry or not, and with 33" tires it loafs along 16-1800 rpms.

[meter swinger]

I keep my dually @ 65 since the 454/400 makes a thirsty situation.
My 78 will handle 75 ok but i'm afraid something will come flying off.
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[1Cobra427]

I usually stick to about 60-65 - 454 engine drinks a lot plus the truck is not daily driver so when I drive it is pleasure and time to relax. Mainly I drive the country roads and avoid highway. More fun that way!!!!!

[bilfman]

I typically roll about 70. I have converted to the 4l80e, 3.73 and 32" tires and I'm at about 2100 at 70. That is with a 454. I found that with the overdrive pulling the big boat the 454 is a little torque starved. I am redoing some 781 heads and changing cam to drop my torque curve to lower rpms.

[Redcap]

Originally Posted by 1Cobra427

I usually stick to about 60-65 - 454 engine drinks a lot plus the truck is not daily driver so when I drive it is pleasure and time to relax. Mainly I drive the country roads and avoid highway. More fun that way!!!!!

Same here. 454, 4.10 gears and 35s...I take the backroads and enjoy the ride.

[Rich84]

65-70 is a nice comfortable cruise (if you don't mind cars a tractor trailers flying buy you at the speed of sound). .373 with overdrive with 30" tires at about 1900 rpm..