Top Crusing Speed?

[motormayhem]

How can I tell what the best fast highway cruising speed for my m1009 is? I am planning on taking it to the mountains this week (200 MI) and I want to get there in a reasonable time, but I haven't driven many diesels and have a hard time judging rpms based on engine sounds. What is the best way to find a good speed to cruse at without blowing the motor? I have 35's so I believe I can go faster that a stock m1009. Right?

 

[ragedracer]

I drove mine up to Pinetop/Showlow last month. I've still got the stock 31"s. I ran it at indicated 70 pretty much the whole way. My speedo is off though, and my wife driving her truck said we were doing 65. I think you would be totally safe in that range.

 

[hobie237]

Have fun: - Dirt Road Magazine - Gear Ratio Calculator - (dirtroad.com)

No reason you can't cruise 65 with the stock tires.

 

[Westech]

I would say 65 for long trips. I do take mine up to 70-75 to and from the Doc office but thats only 20 min on the road or so.

 

[Rebelpride]

Drove mine this weekend, 60-65mph @ 2700-2800rpm netted 19.5mpg, and 55-60mph @ 2500-2600rpm was 21.5mpg.

 

[hobie237]

Using the calculator above:
Stock tires-

55mph RPM- 1836
65mph RPM- 2169
75mph RPM- 2503

Top speed: 101mph

With 35s-

55mph RPM: 1626
65mph RPM: 1921
75mph RPM: 2117

Top speed: 114


Top speed figures are theoretical, I have no idea whether drag would come into play sooner than engine redline, but something tells me it would. As speed increases, drag and engine RPM will cut into fuel efficiency rather rapidly.

 

[motormayhem]

I drove mine up to Pinetop/Showlow last month. I've still got the stock 31"s. I ran it at indicated 70 pretty much the whole way. My speedo is off though, and my wife driving her truck said we were doing 65. I think you would be totally safe in that range.

I'm heading from Tucson to Greer for some skiing at Sunrise. I guess I will keep it around 65-70.

 

[motormayhem]

Also ragedracer did you have any trouble with the altitude up there?

 

[ragedracer]

Also ragedracer did you have any trouble with the altitude up there?

None at all. There was 2-3ft of snow on the ground, and cold as a witch's, well you know.. And it ran great. I didn't notice any loss of power.

I do run Diesel Kleen Power service in every tank too.

 

[maritimer]

well, keep in mind i am at sea level and runnign stock tires.
i can sustain about 90mph without hearing the engine yelling at me to take it easy, i dotn start hearing that till i hit about 100mph. i wouldnt push it to far past 85-90mph though uinless you are familer with the truck as when you pass the 95mph mark she starts to dance and float in the corners. and more then 30 minutes of that at a time will likely start leading to headaches in the engine bay sooner rather then later

 

[mbwarner]

Does the M1008 have the same gearing as M1009, and thus the same cruising speeds?

 

[StreetbikeDepot]

The 1008 has 4.56 gearing while the 1009 has 3.08 I believe......someone correct me if I'm wrong.

 

[hobie237]

Does the M1008 have the same gearing as M1009, and thus the same cruising speeds?

Not even close. 4.56 instead of 3.08 gears, and the stock tire diameters are different. Top speed of an M1008 is around 72mph (I calculated it once, feel free to plug into the calculator I posted earlier) with the stock ~32" tires. Realistic top cruising speed is 55-60mph.

 

[motormayhem]

Update:
Well she ran fine all the way up here at 65mph and got about 25mpg! I was very pleased, however on the way to the ski area the next day it ran fine for the first few miles and then began to loose power and stalled all within about 3 min. Now she wont run for more than about 30sec and the local mechanic told me the injector pump "is full of trash" so he is going to rebuild it for me. I guess I will be back up here next weekend.