Yosemite Trip

[BellaHMB]

Hi All!

We are loving our new Seaside Pearl, package 6 "Gem"! So much so that my 325ci BMW is NOT taking the trip to Yosemite with us! But I have been thinking, are there are any tips about mountain driving that we might need to know? My husband has been reading up on the B gear for downhill braking, but besides that?

Any help is appreciated!

Victoria

[tochatihu]

Check spare tire inflation before you go. Take lots of pictures. Many great hikes if you are so inclined. You can use B gear coming down from Glacier Point.

Perseid meteors overnight 12-13 August.

[tochatihu]

Are double posts deletable?

[jendbbay]

<div class='quotetop'>QUOTE(BellaHMB @ Aug 1 2007, 11:54 PM) [snapback]489081[/snapback]</div>

Hi All!

We are loving our new Seaside Pearl, package 6 "Gem"! So much so that my 325ci BMW is NOT taking the trip to Yosemite with us! But I have been thinking, are there are any tips about mountain driving that we might need to know? My husband has been reading up on the B gear for downhill braking, but besides that?

Any help is appreciated!

Victoria
[/b]

Hi Victoria,

As I mentioned in a different thread, we took our 2007 Touring up to Tuolumne Meadows -- above Yosemite Valley at around 8700 feet, and had only a few moments of trouble. We lost power for about 3 minutes when the temperatures were at the highest, we were climbing, and we had the AC on to recirculating instead of fresh air. We are surmising that you would want to use Fresh Air under those circumstances, but aren't sure exactly why. Switching to it, immediately restored the power. We only got around 43 to 45 MPG with the car fully loaded and three people in it, but that's okay. Our normal summer MPG is 52 plus. We used B when going down step hills.

Enjoy!

<div class='quotetop'>QUOTE(BellaHMB @ Aug 1 2007, 11:54 PM) [snapback]489081[/snapback]</div>

Hi All!

We are loving our new Seaside Pearl, package 6 "Gem"! So much so that my 325ci BMW is NOT taking the trip to Yosemite with us! But I have been thinking, are there are any tips about mountain driving that we might need to know? My husband has been reading up on the B gear for downhill braking, but besides that?

Any help is appreciated!

Victoria
[/b]

Hi Victoria,

As I mentioned in a different thread, we took our 2007 Touring up to Tuolumne Meadows -- above Yosemite Valley at around 8700 feet, and had only a few moments of trouble. We lost power for about 3 minutes when the temperatures were at the highest, we were climbing, and we had the AC on to recirculating instead of fresh air. We are surmising that you would want to use Fresh Air under those circumstances, but aren't sure exactly why. Switching to it, immediately restored the power. We only got around 43 to 45 MPG with the car fully loaded and three people in it, but that's okay. Our normal summer MPG is 52 plus. We used B when going down step hills.

Enjoy!

[Doc Willie]

<div class='quotetop'>QUOTE(tochatihu @ Aug 2 2007, 04:10 AM) [snapback]489122[/snapback]</div>

Check spare tire inflation before you go. Take lots of pictures. Many great hikes if you are so inclined. You can use B gear coming down from Glacier Point.

Perseid meteors overnight 12-13 August.
[/b]

You may want to bring your tire guage, and an inflator if you have one. As you gain altitude, the tire pressure increases. If you are running high pressures to begin with, you could exceed the rating for the tire. So you may have to bleed some air off halfway up the mountain , and then re-inflate at the bottom. After several climbs this gets to be a real PITA, so most settle for lower pressures and take the gas milage hit.

[BellaHMB]

<div class='quotetop'>QUOTE(Doc Willie @ Aug 2 2007, 08:22 AM) [snapback]489184[/snapback]</div>

You may want to bring your tire guage, and an inflator if you have one. As you gain altitude, the tire pressure increases. If you are running high pressures to begin with, you could exceed the rating for the tire. So you may have to bleed some air off halfway up the mountain , and then re-inflate at the bottom. After several climbs this gets to be a real PITA, so most settle for lower pressures and take the gas milage hit.
[/b]

What is the recommended tire pressure range?

Thankyou,
Victoria

[bruceha_2000]

<div class='quotetop'>QUOTE(BellaHMB @ Aug 2 2007, 11:14 AM) [snapback]489267[/snapback]</div>

What is the recommended tire pressure range?

Thankyou,
Victoria
[/b]

Depends on your tires. "Factory spec" is 35 front 33 rear. I set my TripleTreds at 42 front 40 rear. The OEM tires are a bit lacking in traction so I set my wife's at 38 front, 36 rear since I don't think it wise to 'round" them too much. Both have a MAX COLD pressure of 44 psi.

Remember that those are cold tire pressures, i.e. the car hasn't been driven for about 2 hours. You can't drive for a while, then stop and check the pressures and make any assessment as to equivalent "cold tire" pressure. If you drove for 2 hours, then let air out until the tires read 35 front, 33 rear, you would find they were a LOT lower when you checked them the next morning. While it is possible Doc Willie has a valid point about the air expanding at higher elevations, I really don't know how you could reset them unless you stop for a really long lunch. If it makes you feel any better, MANY years ago, I drove from L.A. to 10,000 ft near Mono Lake and had no problems with my tires. Maybe it isn't a very serious problem?

Additionally, when I bought my car (200 miles from home, about half interstate at 65 MPH) the dealer apparently hadn't thought to check the tires. I checked them the next day and one was reading 49 PSI cold. Given I didn't blow it, I think there is a pretty large safety margin.

[BellaHMB]

<div class='quotetop'>QUOTE(bruceha_2000 @ Aug 2 2007, 11:52 AM) [snapback]489335[/snapback]</div>

Depends on your tires. "Factory spec" is 35 front 33 rear. I set my TripleTreds at 42 front 40 rear. The OEM tires are a bit lacking in traction so I set my wife's at 38 front, 36 rear since I don't think it wise to 'round" them too much. Both have a MAX COLD pressure of 44 psi.

Remember that those are cold tire pressures, i.e. the car hasn't been driven for about 2 hours. You can't drive for a while, then stop and check the pressures and make any assessment as to equivalent "cold tire" pressure. If you drove for 2 hours, then let air out until the tires read 35 front, 33 rear, you would find they were a LOT lower when you checked them the next morning. While it is possible Doc Willie has a valid point about the air expanding at higher elevations, I really don't know how you could reset them unless you stop for a really long lunch. If it makes you feel any better, MANY years ago, I drove from L.A. to 10,000 ft near Mono Lake and had no problems with my tires. Maybe it isn't a very serious problem?

Additionally, when I bought my car (200 miles from home, about half interstate at 65 MPH) the dealer apparently hadn't thought to check the tires. I checked them the next day and one was reading 49 PSI cold. Given I didn't blow it, I think there is a pretty large safety margin.
[/b]

Thanks so much! Very helpful!!

Victoria

[Danny Hamilton]

<div class='quotetop'>QUOTE(Doc Willie @ Aug 2 2007, 08:22 AM) [snapback]489184[/snapback]</div>

You may want to bring your tire guage, and an inflator if you have one. As you gain altitude, the tire pressure increases. If you are running high pressures to begin with, you could exceed the rating for the tire. So you may have to bleed some air off halfway up the mountain , and then re-inflate at the bottom. After several climbs this gets to be a real PITA, so most settle for lower pressures and take the gas milage hit.
[/b]

Is this true? Where does the extra pressure come from? This sounds backwards, I always thought that air pressure dropped at higher altitudes.

[PA Prius]

Victoria,

I'm jealous. We returned from our 7,500 mile trip three weeks ago, including Yosemite. It was wonderful and I want to go back!

Since we were fully loaded, I had our tires at 45/45. At highest elevations they reached 50 psi. I'm thinking the tire manufacturers must include the possibility of altitude changes when setting their maximum recommendations.

We rarely used B gear, it sends the engine racing, especially when the battery is fully charged. Our driving was such that minimum brake use sufficed. Since we were camping up at Bridal Veil Falls Campground (beautiful and not full) we made the trip down to the valley (from Glacier Point) four or five times. No problem, and we even averaged 50 mpg those days.

If you are interested in reading more on our trip see either--

http://www.priusonline.com/viewtopic...=11065&start=0 (forum, comments welcome!)
http://www.priusownersgroup.com/?page_id=2840 (refined report with a few pics, including fromGlacier Point)

Have a wonderful trip and let us know how it went!

PA P