RE: All wheel drive question

[Treacherous]

I picked up a '15 Mazda CX-5 AWD GT w/tech about a month ago. I love the driving dynamics of this vehicle. I saw enough videos and reports on forums that it should do fine in the snow. Engine has a timing chain as well so that helps in the long term maintenance costs.

30+ MPG for an AWD CUV on the highway isn't too shabby either. I put a class 3 hitch on it. It is way overkill but it will tow 2K pounds.

I know this is a mud video but does show it can do more than asphalt.




5 Star on safety all around including the new small overlap test.



It may not be the best AWD vehicle but during the non-snow periods it drives like an AWD Miata. It gives my Infiniti G35x a run for the money in the corners.

 

[Mt Bob]

Like!

 

[jharkin]

I'll see if I can dig it up. Had to do with aluminum heads if I recall correctly.

I thought that all cars with aluminum heads and aluminum engines are particular about anti-freeze. The other issues is that the ultra long life blends now put into a lot of cars at the factory are very specialized and not always interchangeable.

Honda's long life AF is blue... and every Honda mechanic Ive spoken to warns to never use anything else. Toyota's long life mix was red and now they have a pink one and also they dont recommend using anything else.

BMW also makes a blue AF, which Ive read is not interchangeable with blue Honda.

And then there was the GM Dex-cool (orange) debacle.. which was also implicated in head gasket failures when used to its 100k rated life.


Its been a long time since I saw a new car that actually came with old fashioned Prestone Green AF from the factory. Times have changed, there are many different mixes of AF now.......

 

[jharkin]

Be aware that some cars, like my Ford, have tire pressure devices attached to the rims. Aftermarket rims don't have them, and you'll get tire pressure warnings constantly. A friend of ours bought a Saab and had the same problem. A piece of tape over the light "cured" it until the summer rims went back on the car.

Those are called TPMS sensors. They have been a NHTSA mandated safety feature on all new vehicles sold since 2008. There are a couple ways the sensors work but the most common is integrated into the valve stem. These are obvious as instead of a rubber valve you will see a metal unit that screws in.

Most tire shops can transfer the factory sensors to current production aftermarket rims made to take them, or install aftermarket sensors (i believe there are even ones that work with old style rubber stems) and program them to the vehicle.

http://blog.tirerack.com/blog/selec...ure-monitoring-systems-on-after-market-wheels

 

[RustyShackleford]

Those are called TPMS sensors.

My girlfriend's new (a couple years back) Mazda had some sort of tire-pressure sensing system. One day while checking my tires (I don't have 'em), I decided to check hers too. They were about 5psi low, but apparently the sensors were not warning of low pressure. So I have the impression they'll warn of gross under-inflation for people that are kind of clueless about cars (avoiding sexist remarks but not that helpful for those of us who like to keep within a psi of so of optimal inflation for handling, tire wear, economy, etc.

 

[jharkin]

My girlfriend's new (a couple years back) Mazda had some sort of tire-pressure sensing system. One day while checking my tires (I don't have 'em), I decided to check hers too. They were about 5psi low, but apparently the sensors were not warning of low pressure. So I have the impression they'll warn of gross under-inflation for people that are kind of clueless about cars (avoiding sexist remarks but not that helpful for those of us who like to keep within a psi of so of optimal inflation for handling, tire wear, economy, etc.

They are a safety device and I believe the idea of the rule was to warn people if their tires where low enough to have a potential blowout (supposedly it came about as one of the reactions to the Firestone blowout problems in the 90s). I believe they have to be something like 25% or 10psi low to trigger.

 

[heat seeker]

Most tire shops can transfer the factory sensors to current production aftermarket rims made to take them, or install aftermarket sensors (i believe there are even ones that work with old style rubber stems) and program them to the vehicle.

http://blog.tirerack.com/blog/selec...ure-monitoring-systems-on-after-market-wheels

Good to know - thanks!

 

[TradEddie]

On the subject of TPMS, some cars will automatically disable 4WD/AWD functionality if TPMS detects a fault. Something to remember if you do the "tape fix". One of my previous cars flashed the cruise and AWD lamps when the TPMS light was on, this was to indicate that those functions were disabled. Not sure if it was the Subaru or not.

Subarus are great in mud, I once towed an Econoline Van uphill out of a muddy grass field, but what impressed me most was the lack of fresh skid marks under the Subaru tires, a testament to how quickly the system reacts to slipping tires. That was with the amazing factory Michelin tires on my 1998 Outback, but the factory Pirellis on the newer model were abysmal, I doubt it would have been so easy with those.

TE

 

[bobdog2o02]

I have had many subarus, i like that they are easy to work on. a set of metric sockets and box wrenches and your set.... I have done timing belts, trans swaps and valve train work. I also have a '96 Jeep XJ Cherokee, give me a subaru for bad weather any day, also for twisty roads. The center of gravity for a subaru sits just above the axle line. Boxer engines sit sooooo low in the car. you would not regret a subie.

 

[bobdog2o02]

The subaru "System" is a viscous differential. seamless not mechanical/ non electrical engagement. its a true all time all wheel drive system. Also subaru uses many distribuition percentages. Most subarus are 60/40 or 70/30 biased to the front end to reduce oversteer in slick weather.

 

[TradEddie]

The subaru "System" is a viscous differential. seamless not mechanical/ non electrical engagement. its a true all time all wheel drive system. Also subaru uses many distribuition percentages. Most subarus are 60/40 or 70/30 biased to the front end to reduce oversteer in slick weather.

I believe that is generally only true for manual transmission Subarus. For automatic transmissions, the front/rear distribution is (usually) a computer controlled clutch. There are so many variations of AWD even within Subaru models, that it's hard to get a simple answer for any given model/year behind all the semi-tech sales pitches. See below for a non simple but still incomplete answer:

http://www.cnet.com/news/not-every-subaru-all-wheel-drive-system-is-created-equal/

On my 1998 Outback, I could feel the central clutch sending more power to the rear wheels when I hit the gas exiting a bend, it was almost like a slight gear change, but with the sudden sensation of switching to the feel of a RWD car. I could not feel this on my later Outback, but I could not find out if this was because the shift was now more subtle, or no longer programmed.

TE

 

[bobdog2o02]

I believe that is generally only true for manual transmission Subarus. For automatic transmissions, the front/rear distribution is (usually) a computer controlled clutch. There are so many variations of AWD even within Subaru models, that it's hard to get a simple answer for any given model/year behind all the semi-tech sales pitches. See below for a non simple but still incomplete answer:

http://www.cnet.com/news/not-every-subaru-all-wheel-drive-system-is-created-equal/

On my 1998 Outback, I could feel the central clutch sending more power to the rear wheels when I hit the gas exiting a bend, it was almost like a slight gear change, but with the sudden sensation of switching to the feel of a RWD car. I could not feel this on my later Outback, but I could not find out if this was because the shift was now more subtle, or no longer programmed.

TE

Not to make this a pissing contest but for the past 20years , i believe, this is the basic configuration. Note item 9 " Viscous Coupling". The reason you feel more power added to the rear is the slipping front tires are turing the shaft from the front and "Drag" the coupling attached to the rear. The car is always dragging the rear tires until there is front tire spin intitiating the Viscous action and turning the rear wheels. It works like two dinner plates in the sink water. try to turn just one when theyre stuck together.

Subaru simply changes the distance between the plates in the coupling or changes the oil weight to change the AWD ratio.

 

[bobdog2o02]

also in your cnet thread, the subaru cvt trans has only been avaiable for two model years now and the STI variable diff is NOT common as there are far more base model foresters and outbacks running around than STI race spec cars.

 

[TradEddie]

Like most pissing contests, we're both a little right, but everything I have ever seen on Subaru's website and literature indicates that the viscous coupling center diff is only used with manual transmissions (since demise of the SVX anyway). Some auto transmissions do use viscous rear diff.

http://www.subaru-global.com/tec_awd.html

 

[bobdog2o02]

Like most pissing contests, we're both a little right, but everything I have ever seen on Subaru's website and literature indicates that the viscous coupling center diff is only used with manual transmissions (since demise of the SVX anyway). Some auto transmissions do use viscous rear diff.

http://www.subaru-global.com/tec_awd.html

If you read a little closer in the 4spd auto it says ets electronically controlled but the it is modulating a viscous diff with a servo.

 

[firefighterjake]

Soooo . . . Subaru AWD is better than others . . . or is the general consensus that in the real world driving on slippery, snow or ice covered roads just about any AWD will work fine and not be noticeable vs. Subaru?

And of course . . . seems like most everyone agrees that Snow Tires trump All Seasons.

 

[firefighterjake]

Personally I suspect my wife is leaning towards the XV Crosstrek from Subaru . . . although I think it would be nice to try the Mazda CX-5 and Nissan Rogue.

 

[TradEddie]

If you read a little closer in the 4spd auto it says ets electronically controlled but the it is modulating a viscous diff with a servo.

We'll have to agree to disagree, there may well still be a viscous coupling which acts without computer control, but my original point remains that most, if not all recent (late 90's onward) automatic transmission Subarus have an active (computer-controlled) component to the center differential, but more importantly, that there are very perceptible differences in how or when that computer control functions in different model years. In my case, a 1998 vs 2005 2.5i auto Outback. I can't say which worked better, just that I could feel it happening on the 1998 model, not on the 2005. My suspicion, given that everything but the radio on the 2005 model was crappier, is that later models used a simpler, cheaper system, however it may well have been a more refined system where the change in torque distribution was more gradual.

If you think the cnet article was complex, take a look at this one: http://www.awdwiki.com/en/subaru

TE

 

[Ashful]

Soooo . . . Subaru AWD is better than others . . . or is the general consensus that in the real world driving on slippery, snow or ice covered roads just about any AWD will work fine and not be noticeable vs. Subaru?

I stick by my statement. Give me an Audi Quattro over a Subaru, any day.

Just sell the Audi before the warranty runs out!

 

[TradEddie]

I stick by my statement. Give me an Audi Quattro over a Subaru, any day.

Just sell the Audi before the warranty runs out!

Agreed for sure on the second point, or at least before 90,000 miles, but the entry level AWD A3 is $34K, A4 is $37k you can buy two regular Imprezas for that. The only fair comparison of Subaru to an A3 or A4 would be the WRX STI.

TE

 

[bobdog2o02]

... An A4 is comparable to a wrx. An S4 is comparable to an STI.......

 

[TradEddie]

But for anyone older than 25, the Audis look 100 times better than any WRX. A few years ago there was a limited edition non-ricer stealth WRX STI, I was very tempted but I didn't bite. In fact all Subarus are ugly, except the base Impreza sedan.

TE

 

[bobdog2o02]

Says you.....

 

[TradEddie]

IMHO

 

[bobdog2o02]

I have bought all my subies over 100,000 miles. Never any major issues as long as regular maintenance occurs. You even said it, sell the Audi before the warranty runs out. Most people including the dealers think a subie is just getting broken in at 100,000 miles.