Does altitude affect engine and transmission? VIDEO

Yep, mine also does it in 4 lo, you can push the pedal real far in and it just won't shift and accelerate. But put in in s1 or 2 and there is no shortage of power. I think it just comes down to crappy transmission programing, on and off road.

 

That's the point I was making with WW2 engines, there's still O2 but with a SC you can force more in than if it was naturally aspirated so you can somewhat make up HP from sea level.

Probably how it was programmed. Are they redlining on the highway? If so it could be a fail safe with the extra load from going uphill. If not then it's how they programmed the engine to operate.

 

Same here, on a trip to Mammoth with the truck loaded down with 3 people, fire wood, and camping supplies the truck was really struggling at the high altitudes at about 9,000ft.

 

SO why did the altitude NOT affect my second gen? I had no issues ever going all the way up to 11,000'. This damn turd gen is absolutely horrible at high altitudes.

 

Driving in Colorado myself, I suggest you stop letting the truck drive your foot and move the shifter around yourself. Everything I've ever driven up the mountains whines hard up to the tunnel and usually does a terrible job selecting when to downshift automatically, slowing you back down and requiring another hard shift at some point to scream back up to speed. Its just not an extremely powerful vehicle so you aren't gonna get up there at 2000 rpm.

Also does your mpg display show you at 65 going up the mountains of colorado getting 18mpg? That's very good.

 

http://www.wallaceracing.com/braking-hp.php

I had the same problem with my 2013. Supercharger helped but didn't completely get rid of it. Especially with truck full if people and camping gear.

 

Does a dirty air filter affect it more?

 

Same here, I run up and down I-70 a lot and it's making me regret my Tacoma purchase. I love the truck in every other aspect but driving up the hill makes me want to break down and get an F-150.

 

That's probably the only letdown to me on my Tacoma, aside from a few other dinky things. I don't know if it has anything to do with the elevation but I live at ~6k ft and I suffer just getting to highway speed on the uphill I25 ramp to get to work in the morning. Seems like I can manage to get to about 45-50 pretty well if I'm heavy on the gas, but then I hit that next elephant suddenly in the bed gear and getting from mid 50s to mid 60s feels like I need another 5 miles of ramp to build up enough momentum. The ECT button seems to help with that for me. I'm also used to a 4 cylinder hatchback so I think I need to learn to be heavier on the gas with a truck. I'm hoping with time I will better learn the power bands and know when to give it more to keep it in that gear. I'm terrified to drive it on 70 or up 24 into the mountains though, sounds like my fears are somewhat warranted. Have not tried S mode yet, that may help in specific circumstances.

 

I wish my Taco could fly to higher altitudes, but it stays on the ground, so I’m stuck only driving it to higher elevations.
Tomorrow’s geography lesson: “The Sierra” or “The Sierras”?

- but yeah, when I’m towing or going up long steep grades, especially at higher elevations, I turn off overdrive and switch from D to 4, letting the engine stay at about 4K RPMs. It seems to do best there and keeps a constant speed.

 

Shipped my 87 Grand Waggy to Montana while we were stationed there. Wouldn't run for shit. Had the carb re-jetted while I waited for my FI conversion to arrive. There was a definite power loss from the way it ran in Ga.

 

I wrote this post awhile back for the 4Runner crowd who were complaining about temperature and altitude. Just substitute our HP into the chart. The outcome is the same.

"Many of us have experienced colder than normal temperatures in the past few days. Two days ago I was riding my bike in 70 degree F temperatures in SC. This morning it was 7 degrees F at my house, which is quite a bit of difference. As I was driving this morning, I noticed my TE throttle was more responsive. I knew immediately why but thought I would share it with you guys too.

The Rules:
For every 10- to 11-degree Fahrenheit rise in intake air temperature past 77 degrees, (SAE J1349 standard test correction temperature), you can expect engine horsepower to decrease by about one percent at the same barometric pressure. That works out to a 6.80-percent increase in horsepower for every 1-psi rise in barometric pressure, and a 6.8-percent drop in horsepower for every 1-psi under 14.7 (ambient sea level)
Credit: SAE

Dynojet's rule of thumb is that a 1% increase in power occurs for every 10 degrees F cooler. So,

Our 4Runners have 270 HP at sea level and 77 degrees F.

Alright, now that I have given you the background, here is what I calculated my horsepower was in my TE this morning:

270hp * 1.07 = 288.9 or approximately 290 HP! The 1.07 comes from the differential temperature of tested vs actual. Now, barometric pressure comes into play also and it just so happens that the pressures were within 2 millibars of each other at these different locations so they were a wash.

To conclude, I had around 270 HP on Sunday and 290 HP today. 20 more HP and I did not spend a dime lol. If you guys would like I could make a chart except barometric pressure factors into this equation too. I was lucky and had almost the same pressures even though the altitude is over 2000' different from where I rode Sunday to where I am today. Normally the altitude would have negated any gains caused by temperature. Anyway, just thought it was interesting and you would like to know how temperature affects horsepower either for the good or bad.

These Chart(s) are THEORETICAL! I added a chart on HP vs. Altitude also. It really all depends on air density and altitude or temperature effect density. Here you go:"

 

Took my PriusV (1/2 of Tacoma's engine) on spring break to Moab and Bryce Canyon and car performed just fine. Must be cold air
Looking forward to go back on Tacoma.

 

For me I understand and accept that the truck is going to take a power hit at altitude. It's not a lack of power in my case, it's the transmission continuing to shift up to a gear that it can't hold, lose speed, downshift, accelerate past your desired speed, then shift up to a gear it can't hold...then lose speed again and downshift.

When it "D" it will continue to bounce around, in "D" with cruise set to say 65mph on some of the long climbs it will just stay in the lower gear happily at almost 4k rpms and not shift around constantly. I've gotten to where I just put the cruise control on or switch over to "S" and manually try to keep it in the gear I want.

Hard to stay at an exact speed with cruise control on going up and down I-70 with all the semi's crawling up the hill and people bouncing back and forth between the right and left lanes.

 

They do. Less air means less fuel to keep the mixtures correct which means less power. Carbs went to smaller jets as you went higher which is the same thing.