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Hi all-- I'm new to the world of forums, but I'm finding that even the dealer is a little inexperienced with all of the ins and outs of the T8 XC90, and I wanted to see if any of you smart people could give me some advice. I've had my T8 for less than a week. One of our frequent drives is from the Bay Area up to Lake Tahoe. This is about a 3 hour drive (up to 5 with traffic on a Friday evening). When we get up to the mountains, we sometimes need AWD to get through the snow. The dealer's recommendation was to do this in Save mode, to make sure there's plenty of battery to use the AWD. When I made this trip Friday I started with 1/4 battery as I had been running errands earlier in the day and didn't have time to fully charge (charger being installed this week). I placed it in Save, and assumed, given the heavy traffic, that the battery would regenerate by the time we hit the snow. However, the battery never went past 1/4 full. It didn't seem like it charged at all in Save mode.

Does anyone have any suggestions of how best to manage the settings on a drive like this? Any idea, even with a full battery, how long you can drive in AWD? The car did drive like a dream in the snow... very sure footed. It drove right around a Jeep that was spinning it's wheels on an icy part of a steep hill. (Sorry Buddy!) And can I also just add WOW do I love the adaptive cruise control in that heavy stop and go traffic-- so much more relaxing when I just have to steer!

Thanks in advance for any suggestions and advice! Cheers!
 

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One of the things I wish we could do with the T8 is when you select save mode ... is bump up the amount of energy left in the battery to save. For example: similar to what you noted - if you are down to 25% battery remaining and then switch to save mode - the vehicle will try to keep that amount. I have no idea how efficient the engine powered generator is - but I think it would be nice to switch to save mode (at say 25%) and then bump it up to 50% or 75% (with the intent to fill the battery).

What I found works for me: when my journey calls for Interstate highway (65 mph / 100 km/h) driving I typically use either hybrid or pure to get to the highway and then switch into save mode - with the idea that it is much more efficient to use the battery on non-highway roads and stop and go traffic. When I get off the highway I switch to pure or hybrid.

What I have not had a chance to do is see how much battery power is recovered by driving say a hour at highway speeds. I also wonder if the engine driving generator charges better at highway speeds / RPM - or is it the same whether your're on the highway versus heavy traffic.

I'm on the other coast (New England) and we have only had one snowfall where we've had to plow - and I don't think any snow has lasted more than 24-hours. Very strange winter - reminds me of Seattle or The Netherlands. Alas - I have not had the opportunity to go play in the snow other than a brief encounter with a few inches in a parking lot. I have the same question though about driving in AWD ... and if my memory is correct, I think the manual suggested AWD mode was not for highway speeds though.

Saw on the news I-80 pile-up in Truckee - stay safe!
 

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One of the things I wish we could do with the T8 is when you select save mode ... is bump up the amount of energy left in the battery to save. For example: similar to what you noted - if you are down to 25% battery remaining and then switch to save mode - the vehicle will try to keep that amount. I have no idea how efficient the engine powered generator is - but I think it would be nice to switch to save mode (at say 25%) and then bump it up to 50% or 75% (with the intent to fill the battery).
Can you even do that? I thought that the battery energy level can never exceed 33% charge, while in Save mode.
 

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Not a t8 owner but I have two thoughts on this. One, as far as I understand it awd is always available, via reserve battery power which is replenished if needed by the generator. Two, using the generator as a charging point is inefficient so I don't see the value in using it to charge past 33% or whatever the cap is.

For typical awd needs you would only need a very small amount of energy for whenever one of the front wheels slips. Unlike 4wd which has all four wheels constantly under power. I wouldn't worry about conserving battery for awd purposes at all.
 

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From the Volvo support site:
"The rear wheels in the T8 are powered using the electric motor. Your XC90 is equipped with a powerful engine driven generator called an Integrated Starter Generator (ISG). The ISG provides electric power on demand, meaning AWD is always available regardless of the battery's available power."
 

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Can you even do that? I thought that the battery energy level can never exceed 33% charge, while in Save mode.
Actually - good question. I use save a lot - and the battery level will never go below the point where you turn save mode on. Still - in save mode it often uses the electric motor (same is in hybrid or pure) to get you moving and then the engine kicks in. I've never seen the battery really go above, or below, the save mode point when in save mode.

My idea / thought was ... say you're going to take a 10 hour drive, mostly highway. You use 75% of your battery to get from home to the highway and then switch into save mode for highway driving. The driver's display will show the 25% mark and not let the battery charge drop below that. I would think that it may be interesting to have the engine replenish the battery's charge, as much as it possibly could.

I suspect that while the integral starter generator can charge the battery - it is probably not very efficient at doing so ... and maybe this is why Volvo limits the amount of engine recharging.
 
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