Hi, all!

I've been a lurker here off and on while trying to learn more about the 1500 Sierra/Silverado hybrids.

This has been the most helpful resource yet for information about this difficult-to find truck, so thanks! I have been living away in New Zealand/Tasmania for 3 years, but am heading back to Alaska for good in about 5 months. I'll be buying a vehicle, and a 2010 GMC Sierra Hybrid is the frontrunner for a number of reasons.

Two questions I can't seem to find answers for anywhere, though:
1) Effects of extreme cold on the battery? Some Priuses (Priusi?) developed nonfunctioning batteries at -40 or -50. I'll be spending some time in Fairbanks in the winter, and 50 below is NOT the time to discover that you can't start your truck.

2) Can I put slightly larger tires on safely and without screwing up the warranty (perhaps with a mild body lift of 2-3 inches)? Yes, I know this may affect mileage. I also am aware that this would put more stress on the drivetrain. I am NOT aware of whether this would cause real damage or issues with regenerative braking or the complex transmission.

I will be using the 4WD for some reasonable off-roading, though nothing terribly bad - some increased clearance would be nice. Likely 33 inch tires if possible.

I sent an e-mail to the GMC folks, but got a pretty generic e-mail in response with no real information. Lots of junk e-mail now, though!

As a bonus question, I am freakishly tall at 6'6", but want a moonroof. Anyone of a similar height with experience to give?

Thanks in advance.

 

Hi there ...

I don't know the answer to the first question, but I do know that for some reason Chevy doesn't offer the cold weather option on their hybrids. Ambient temperature does have an effect on efficiency but I am not aware of any operational issues relating to extreme cold. This might be a question best answered by an Alaska based Chevy dealer.

On your second question ... some good info here: https://www.greenhybrid.com/discuss/...upgrade-27164/ The leveling kit that I've heard the best reviews for is the CCM 2.5" front/1" rear levelling lift kit ... here it is on a non-hybrid Tahoe: http://www.tahoeyukonforum.com/forum...ad.php?t=28652

As far as warranty considerations, they are always the same with all vehicles ... namely the dealer has to provide factual/real evidence that any modification made to the truck has directly caused a warrantied part to fail. No one modification can void an entire warranty, just the parts affected by the mod. More info: http://en.wikipedia.org/wiki/Magnuson–Moss_Warranty_Act

As always dealers vary in their attitudes, mine honors all aspects of my warranty even when I had her lowered on 24s.

Regarding head clearance ... I am 6.1 and with the seat at full height my head clears the liner by a little over 2", and about 6-7" with the seat all the way down, though I must say the latter would involve a rather odd way to drive. Not sure what effect not having the moonroof would have but I'm thinking this is one of those deals that you just need to discover via a test drive.

On a passing note, although there's no evidence that I have seen making the hybrids less 'rugged' than their non-hybrid counterparts, I slightly question the idea of going with a hybrid truck knowing that extreme climate and significant off road driving is involved. For the same price one could get a sick Sierra Denali, sacrifice some mpg, and have a beast of a truck that requires a lot less stress wondering how it will react under duress.

Hope some of that long windedness helps a little.

Cheers!

 

Thank you, HyHoe - a very thoughtful answer!

I sent an e-mail to the Anchorage dealer with no useful response. Just managed to make it on their e-mail list. Perhaps Fairbanks would be a better place to ask with regards to cold-weather issues - I will try there next. I did not realize that the cold weather package was not available on the hybrids. Typically, the appropriate parts can be added by the dealer (or any mechanic) but it does beg the question why they don't offer that in the first place.

Thank you for the links on the mild body lift, exactly what I am looking for. Also good info on warranty issues. Still a bit sticky, I guess, if they claim that bigger tires may put more torque or change the appropriate programming on things like regenerative braking modules, but does make things a bit easier on my mind.

I may have overstated the amount or level of four wheeling I am likely to do in Ice Road Trucker-style conditions. I'm most likely going to be living in south-central AK around Anchorage, where the coldest it gets is typically 20-30 below. Only on rare occasions am I likely to head out into the boondocks north of Fairbanks on the haul road. But you are certainly right - proven technology is safer technology in those conditions.

And thanks for the thoughts on height. Silverado/Sierras have the highest headroom of all the full-size trucks, sounds like I will fit. Getting pretty tired of having to duck just to see more than 200 yards ahead.

All-in-all, I'm still torn, but with more information at my fingertips now. Think I will write the Fairbanks dealer. Any other thoughts would be appreciated. If Ford's Ecoboost were a financial option, might consider that, but I like to allow new technology to bake in for at least a year before taking the plunge, and a new one just isn't in the cards. A Toyota Tundra is #2, but the gas mileage does make me cringe a bit.

Cheers from New Zealand

 

When you head out into the boonies... how long will you let the truck sit before driving again? The sheer mass of the 2 mode trans and the HV battery in the passenger compartment means that it will take almost 20 hours for them to chill to ambient outside temperature.

In 8 hours of sitting they will cool off significantly but not enough to cause problems.

Ask any of the owners here now that winter is comming to look at the DIC for trans temp at shut off. Then look again on the next morning's start.

If it is going to sit below minus 30F for a few days it will be a good idea to plug it in. There are some 120V heat pads that are silicone mats less than 1/8 inch thick available from Cole-Parmer Scientific Supply

http://www.coleparmer.com/catalog/pr...sp?sku=0312520

120V AC 50 watts 2" wide 5" long. Others available.

These pads are tough and thin. They can easily slide in under a flat smooth surface below the HV battery. Battery power on Ni Mh is better than Lithium ion. Keep the cells above -20F and there will be no problems. Then if you drive a long distance 2 plus hours the cabin will warm up enough to get the battery fully re-charged. Any battery needs to warm up some to fully re-charge. Once fully warmed up you will get Auto-Stop even at -40.

 

Greetings, Hillbilly_Hybrid!

I like the idea of the heating pad under the HV battery. I have typically used a heating element for engine oil, a second for the tranny, and a battery blanket for the 12v battery on a normal engine. Most places outside (including grocery stores) have plug-ins up in Fairbanks. If I am going fishing, it is NOT likely going to be -50, quite honestly, unless the weather takes a surprise turn while I am out there. Toes and ears are fairly valuable.

Still - better plan for the worst and hope for the best. It would be nice to know how the Sierra/Silverado handles in that kind of weather, even if it's just to leave at someone's house for a day or two. When I first moved up to Fairbanks (in the winter), I wasn't able to get my car winterized immediately. Result? After 3 days of nonuse, everything froze up and I wasn't able to start it again for 2-3 weeks until the temps hit a balmy -10 or so. Lesson learned!

 

I think I saw some hybrids in the snow in hillbilly hybrids album, if I'm not mistaken.

 

Regarding off road and snow I have a couple of tips that might work for you.

I have a 09 Silverado truck rolling on 32.80" Diameter tire since new with no issues at all.

I levelled the front using bilstein shocks.

http://www.bilsteinus.com/fileadmin/...WebArticle.pdf

Installed them in the last notch and clear my tires no problem even on twisting ditches.

Now the 4wd system is almost the same of the non hybrid truck. One tip is to purchase the Z71 Skid plates for under body protection. Hybrid truck came with non. Only a plastic one on the front beneath the radiator for water splash protection.

GM PART # 15843753 <-----Aluminum Skid plate protecting oil pan
CATEGORY: Engine Oil Pan/Reinforcement
PACK QTY: 1
GM LIST: $39.24
OUR PRICE: $23.26

GM PART # 15049809 <----- ALuminum skid plate protecting transfer case
CATEGORY: All
PACK QTY: 1
GM LIST: $32.97
OUR PRICE: $19.54

GM PART # 11518341 <------ Self tapping metric bolts (You will need eight (8) of these, four (4) per plate)
CATEGORY: All
PACK QTY: 1
GM LIST: $6.46
OUR PRICE: $3.84

No drilling, just bolt on installation.

Now, the Hybrid truck have an Electrical Power Steering system witch is awesome and stronger than the hydraulic system. But as everything it has it's own weakness.

http://blogs.cars.com/.a/6a00d83451b...9582970c-800wi

In the picture above look at the plastic boots on the steering terminals.

You must replace them for neoprene or any good rubber boot. Sealed ones.

The electric nature of the EPS system has no oil in the steering rack. Now that is no problem until your HARD PLASTIC cover boot cracks open due to any offroad debris. It let water in (snow probably in ur case that will turn in water).


Now, the water will be push in the steering rack body and will ruin in no time the 3 main bearing inside.
I have 6 close to me cases with the same problem. I took mine apart and the center bearing is just made for the company that build this things. so is not available in the market yet.

I had to purchase a new steering rack for $1100

Called and emailed GM about this, and the wrote me back telling me they had no issues reported. Just mine. Then I sent pics and 7 VIN numbers of the trucks (one Escalade in that party too) and the parts damaged. Then I had no response.

As soon as I got my new Steering Rack I changed the boots for some Generic Good quality rubber ones (mine and my friends) and none of us had any issue off road since then.

The system is good if you stay on road or the occasional dusty back road. But for mild off road and up is a no no !

Hope this helps, and good luck purchasing your hybrid. Is a great truck overall !

 

That's some excellent information there Gabe ... I'm just sorry you had to go through such expense to discover it.

Hope you're keeping well.

PS. There are periodic visits from GM customer service on tahoeyukonforum. It might be too late for the steering rack issue but in my experience they can really assist people in resolving their issues with GM.

Cheers!

 

Thanks HyHoe,

Just my 2cents trying to help ppl.

It was never my intention to get a free replacement from GM. It was to make them aware and take proper measures to prevent any other GM hybrid owner to experience this.

I'm a die hard GM addict !!!!

I just want GM to be the best out there... that's all.

This problem was a long time ago. Now I know that Nexteer is the company that makes this EPS for GM.
http://www.nexteer.com/premium_eps.html

Maybe I'll send them an email with my suggestion sometime soon !

 

Time Hybrid,
Two things.. How do you go about putting the rubber boots on the EPS, and where can you find some sealed ones?

Thanks