Based here in Denver, recently bought a place in the mountains, so I need to do I-70 and an 11,000ft 3-lane(2+1) pass to get there. It’s all paved except for the last mile, but that last mile is a fairly steep dirt road to the cabin at 8600ft/2.6km.
While most people know Denver is The Mile High City, going west gets you about 8-9000ft pretty fast when going up I-70. The tunnel under the divide is 11,000ft/3,300m or so. There are lots of 6%+ grades, to deal with. The bigger issue is that we are talking about an interstate highway, and high speeds- 80mph isn’t uncommon. But then you have trucks and people driving the ‘speed limit’ in the left lane. It’s mostly 2 lanes each way. It’s also all torn up west of denver until 2029 as they try to add lanes and remove rock slide threats. And these driving habits extend into winter when there is 100 yards of visibility, a couple of inches of snow and unknown layer of ice on the road, and some pretty gnarly winds.
I’ve only had the IG up in this in the winter a couple of times, especially with my KO3s. Great traction in standard or center diff lock in high did fine.
What I did want to talk about is the performance in summer, which doesn’t preclude ice in the story…
While the I70/Eisenhower tunnel is fairly straightforward, I actually have to take an 11,300 foot pass to Winter Park. I’ve done it a number of times in various weather and time of day. What I wanted to focus on was the performance on Berthoud pass (11,300ft/3400m). It’s two lanes up, one down. For perspective, from Wikipedia:
“However, the pass is one of the most notoriously difficult passes in Colorado for motorists, based on its height as well as the steep grades on both sides (6.3%) and the large number of switchbacks on the southern side of the pass. At least 55 avalanche paths have been mapped on Berthoud Pass, some of them intersecting U.S. Highway 40 and some of those intersecting the roadway at multiple points on the pass.”
The speed limit is like 40, I’ve never really paid attention. The IG, even with a fair load is faster than I need it to be, especially considering the switch-backs. The straightaways, even with the 6% grade, I can accelerate on and frankly, I’ve never been passed going up either side. While the IG might not have the highest HP, that gearbox works wonders- and the twin-turbo accelerates it from 25 to 60 at 10000ft with no problem on the short straightaways. It claws for altitude like a Kurt Tank TA-152.
The interesting thing is on the way down. Especially with the 285/70R17 KO3, and an airfoil shape of a barn, with the 8 speed gearbox, coming down is a breeze. The 20mph switch backs require some braking, since I like to keep the speeds higher, but with all that tire and air drag, you could come down slowly and steadily as you want. THe really cool thing is coming down I70 back into Denver. The grade isn’t consistent, but I actually have to use the gas more than I have to use the brakes- and that’s coming down. Keeping 75mph in 6-8th gear, and having to add power when things flatten out. Totally makes coming down very manageable. All of this is of course when traffic isn’t gunking things up.
And that is in good weather. I had to do the Berthoud Pass Southbound, in the dark, in the middle of a hail storm that put down 2+ inches of hail on the pass, with lightning flashing all around and seemed to be at times below us. My MIL was with me, lifetime Coloradan, and she said that it was the worst storm she had ever been in. The hail was so loud that we couldn’t talk. It wasn’t big enough to cause damage, but intense. No problem for the IG.
So I wanted to post this as a real world data point for how the IG performs. And adding in the altitude for more extreme conditions. I couldn’t use any more power than the IG has. On Floyd hill heading east (up-hill, 6% grade) the IG will accelerate from 40 to 80 going uphill. I know there are faster cars out there, my wife’s X5 V8 twin turbo, but I’ve never been passed on that hill. The IG is ‘fast enough’ or more importantly, faster than I can safely drive it. And it really shouldn’t be that much of a surprise, what do old 110s have for power/weight- and no turbo for altitude.
While most people know Denver is The Mile High City, going west gets you about 8-9000ft pretty fast when going up I-70. The tunnel under the divide is 11,000ft/3,300m or so. There are lots of 6%+ grades, to deal with. The bigger issue is that we are talking about an interstate highway, and high speeds- 80mph isn’t uncommon. But then you have trucks and people driving the ‘speed limit’ in the left lane. It’s mostly 2 lanes each way. It’s also all torn up west of denver until 2029 as they try to add lanes and remove rock slide threats. And these driving habits extend into winter when there is 100 yards of visibility, a couple of inches of snow and unknown layer of ice on the road, and some pretty gnarly winds.
I’ve only had the IG up in this in the winter a couple of times, especially with my KO3s. Great traction in standard or center diff lock in high did fine.
What I did want to talk about is the performance in summer, which doesn’t preclude ice in the story…
While the I70/Eisenhower tunnel is fairly straightforward, I actually have to take an 11,300 foot pass to Winter Park. I’ve done it a number of times in various weather and time of day. What I wanted to focus on was the performance on Berthoud pass (11,300ft/3400m). It’s two lanes up, one down. For perspective, from Wikipedia:
“However, the pass is one of the most notoriously difficult passes in Colorado for motorists, based on its height as well as the steep grades on both sides (6.3%) and the large number of switchbacks on the southern side of the pass. At least 55 avalanche paths have been mapped on Berthoud Pass, some of them intersecting U.S. Highway 40 and some of those intersecting the roadway at multiple points on the pass.”
The speed limit is like 40, I’ve never really paid attention. The IG, even with a fair load is faster than I need it to be, especially considering the switch-backs. The straightaways, even with the 6% grade, I can accelerate on and frankly, I’ve never been passed going up either side. While the IG might not have the highest HP, that gearbox works wonders- and the twin-turbo accelerates it from 25 to 60 at 10000ft with no problem on the short straightaways. It claws for altitude like a Kurt Tank TA-152.
The interesting thing is on the way down. Especially with the 285/70R17 KO3, and an airfoil shape of a barn, with the 8 speed gearbox, coming down is a breeze. The 20mph switch backs require some braking, since I like to keep the speeds higher, but with all that tire and air drag, you could come down slowly and steadily as you want. THe really cool thing is coming down I70 back into Denver. The grade isn’t consistent, but I actually have to use the gas more than I have to use the brakes- and that’s coming down. Keeping 75mph in 6-8th gear, and having to add power when things flatten out. Totally makes coming down very manageable. All of this is of course when traffic isn’t gunking things up.
And that is in good weather. I had to do the Berthoud Pass Southbound, in the dark, in the middle of a hail storm that put down 2+ inches of hail on the pass, with lightning flashing all around and seemed to be at times below us. My MIL was with me, lifetime Coloradan, and she said that it was the worst storm she had ever been in. The hail was so loud that we couldn’t talk. It wasn’t big enough to cause damage, but intense. No problem for the IG.
So I wanted to post this as a real world data point for how the IG performs. And adding in the altitude for more extreme conditions. I couldn’t use any more power than the IG has. On Floyd hill heading east (up-hill, 6% grade) the IG will accelerate from 40 to 80 going uphill. I know there are faster cars out there, my wife’s X5 V8 twin turbo, but I’ve never been passed on that hill. The IG is ‘fast enough’ or more importantly, faster than I can safely drive it. And it really shouldn’t be that much of a surprise, what do old 110s have for power/weight- and no turbo for altitude.
