Last post on Dec 22, 2009 at 12:01 AM
You are in the Toyota Sienna
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Toyota Sienna, Van
#46 of 55 cruise control?
Nov 26, 2007 (12:06 pm)
i wanted to ask if you set cruise control and travel up steep grades, does the new engine require a downshift or does it hold it's gear at the same speed up the incline without problem? thanks in advance. We just got back from a road trip to Washington and through Mt. Shasta our 04 had to down shift to hold 70mph up some grades.
#47 of 55 Re: cruise control? [hause7]
Nov 26, 2007 (1:11 pm)
It will shift down.
Keep in mind the gearing has not changed. It's very tall geared. At 55mph it's barely idling along at something like 1500rpm. At 70 I think it's just barely over 2000 rpm.
As flat as the torque curve is, you hit an incline and it will shift, though mine has only ever shifted from 5 -> 4, never two ratios.
#48 of 55 Re: cruise control? [ateixeira]
Nov 26, 2007 (1:14 pm)
So you would be around 2,500 RPM to pull up a grade 70mph? or would it require more than that? Our current 04 has to go up to 3,000-3,300RPM to pull up some inclines with cruise set 70mph.
#49 of 55 Re: cruise control? [hause7]
Nov 26, 2007 (1:59 pm)
Not sure about the rpm in 4th, but the gearing is the same as yours, so I doubt that will change.
The 3.5l has roughly 10% more torque across the torque band compared to the 3.3l. So there may be a few scenarios where that 10% makes enough difference.
#50 of 55 Re: torque and HP graph for BOTH 3.3L and 3.5L? [ateixeira]
Dec 23, 2007 (9:41 am)
Does ANYONE have a link to a graph for each?
Toyota specifies 87 octane for the 3.3L in the Sienna but states that the 3.3L provides more power on higher octane premium. Does the 3.5L also develop MORE power using premum?
#51 of 55 Re: torque and HP graph for BOTH 3.3L and 3.5L? [hansienna]
Dec 26, 2007 (1:12 pm)
On paper, the 3.3l made 215hp by SAE measures. Figure you lost a few on 87 octane, but it's still probably about 210hp.
One of the few manufacturers that stated HP for both types of fuel was Subaru, when their H6 engine came out. It made 212hp on premium, 208hp on regular. Since power output is similar for the 3.3l Toyota engine, it seems reasonable to conclude there would be a similar HP loss.
Now, to the 3.5l, Toyota states an SAE output of 266hp. This is low for the 2GR, other models make 268-270hp from the same engine. The RAV4 is rated for 268hp even on regular fuel.
Can they make more HP on better fuel? It depends, if Toyota tuned the engines to advance the spark timing, then yes, they could squeeze out another 5hp or so, is my guess.
The catch? We know the 3.3l is capable of running on 87 octane, because that's all that is required. So it was tuned to be flexible enough for both types of fuel.
We don't know, however, if the 2GR (3.5l) is tuned to take advantage of higher octane (by advancing spark timing beyond stock settings). Any answer is just a guess, we don't really know.
Dec 19, 2009 (3:27 pm)
In the 07-10 models with the timing chain (3.5L) how often does the timing chain need to be inspected? is that an easy operation?
Also at some point I would assume it does need replacement- when?
#53 of 55 Re: Timing Chain [tekkamaki]
Dec 20, 2009 (11:01 am)
It should outlive the rest of the van. Something else will give in well before the timing chain does.
#54 of 55 Re: Timing Chain [tekkamaki]
Dec 21, 2009 (2:02 am)
As Ateixera said, it will probably last the life of the engine. Also if ever does start too loosen up too much the timing will start to slip but is very unlikely to fail suddenly and catastrophically like a belt would. There's nothing to do about it in the meantime so don't worry about it.
#55 of 55 Re: Timing Chain [yatesjo]
Dec 22, 2009 (12:01 am)
I race mountain and Cyclocross bikes an find it amazing that I can constantly break chains on a mountain bike- but they last many years on a car. It must be the size of the chain and the shifting action on the bike.