Interesting Day at the Dealer - Routine Maint / Manual Q's

[SE95]

Originally Posted by GBMaryland

So, the two vs four wheels...

On a NON-AWD vehicle, IMO it's a load of poop [trying to be better about the swearing] to rotate the tires.

Consider this:

If you have a front wheel drive vehicle, you are going to wear out the front tires first. Period.

The rear tires, properly inflated, and properly aligned, will outlast the front tires 2 to 3 times as longer.

So, if you are putting 15k a year on the car, you're going to get about 2-3 years out of the rears, and repalce the fronts at least 1 time, probably 2. [This assumes you drive like me.]

The tires in the front will be the same as each other, and so will the rears.

Why would you put yourself in the financial position to have to replace four tires at every time you need tires, when you can just replace the front tires several times? Especially, when the rear wear indicator isn't close to being hit...

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Now, if you have a rear wheel drive vehicle, the logic sorta goes out the window, as you're probably going to go through a set of tires a more regular intervals.

However, you are still repalcing them 2 at a time; tires should be repalced in sets in the rear and the front.

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Note: I'm not talking about different brands in any of my comments. I'm talking about replacing the fronts or the rears with the same model and brand. I've sorta assumed that people would understand that. It's fairly obvious to me that if you are only replacing two tires, they still have to match the other two tires on the car. (Compound formulation, size, etc.)

What I didn't take into consideration with the AWD aspect was the example where different treadware results in a 1/4 inch difference from one differential to another.

That could be pretty significant.

Why would you put yourself in a financial position to buy tires constantly instead of a slightly larger bill further apart? Consider the fact that by rotating regularly you extend the life of ALL the tires. Also consider the fact that you void any warranty your tire has against premature wear or irregular wear (in most cases) when you don't rotate them. Failure to rotate can and will (I've seen it happen) cause your rear tires to cup, which causes a lovely vibration. Also it can cause outside edge wear on the front tires as they are constantly turning and rolling onto their sides... especially on a heavy vehicle.

[GBMaryland]

Originally Posted by SE95

Why would you put yourself in a financial position to buy tires constantly instead of a slightly larger bill further apart? Consider the fact that by rotating regularly you extend the life of ALL the tires. Also consider the fact that you void any warranty your tire has against premature wear or irregular wear (in most cases) when you don't rotate them. Failure to rotate can and will (I've seen it happen) cause your rear tires to cup, which causes a lovely vibration. Also it can cause outside edge wear on the front tires as they are constantly turning and rolling onto their sides... especially on a heavy vehicle.

Valid points... doubt it really applies to Honda Accords, Civics, or Preludes. Never had cupped rears... never had an issue, well over 600,000 miles on those cars.

...of course, they don't weight that much.

[GBMaryland]

Originally Posted by plain OM

And, for a Factory Service Manual go to SOA's tech info site: Subaru Technical Information System - Welcome

Wow... and thought the manuals were expensive!

[SE95]

Originally Posted by GBMaryland

Valid points... doubt it really applies to Honda Accords, Civics, or Preludes. Never had cupped rears... never had an issue, well over 600,000 miles on those cars.

...of course, they don't weight that much.

I've seen it happen on a Focus. Not exactly a heavy car. In fact on that car the rears were cupped so badly you could tell just by looking at them... from 5 feet away!

[rasterman]

Originally Posted by GBMaryland

Wow... and thought the manuals were expensive!

Documentation always seems to be 10x as expensive as production, in any field... the factory manuals for my old carbureted, air cooled VWs were $80 in 1980s money, and those cars were stone age tech compared to the complexity in "average cheap" cars like today's hondas & subarus.

[GBMaryland]

Originally Posted by SE95

I've seen it happen on a Focus. Not exactly a heavy car. In fact on that car the rears were cupped so badly you could tell just by looking at them... from 5 feet away!

Whoa!

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So I pulled out the various supplements, including the tiny chart maintainance intervals... and then enlarged / merged that with the various places in the owners manual to create a comphrensive one stop location pamflet for the cars.

One for the Outback and one for the Legacy.

I guess I'll rotate the tires this weekend. -grin-

I'm still shocked that given all the stuff the sales team went over, the one thing they didn't stress was that your tires effectively need to be flawlessly close, including wear.

Interesting to me: The maint intervals appear to be every 30K miles, and you only replace the oil filter, oil, air filter, and brake fluid.

It's sorta odd that everything else, except the spark plugs, is "Inspect."

Tires are rotated every 7500 miles with the oil.

I wonder if Subaru will freak out if you use DOT4 synthetic brake fluid? (I have like 6 qts of the stuff laying around...)

[rasterman]

Originally Posted by GBMaryland

It's sorta odd that everything else, except the spark plugs, is "Inspect."

"Inspect" in Subaru manual parlance means "Inspect, and replace/renew if it isn't right." So they are leaving some things open to a judgement call. Some of those items are going to need replacement at every "inspection" interval with your average use, some won't. They just decided that the spread of average usage patterns was too wide to lock it down to a specific replacement guideline.

Originally Posted by GBMaryland

Tires are rotated every 7500 miles with the oil.

I wonder if Subaru will freak out if you use DOT4 synthetic brake fluid? (I have like 6 qts of the stuff laying around...)

Do yourself a favor and "inspect" the oil at a shorter interval, just until you have a feel for whether your engine consumes any oil over time. Some do, some don't, and you really really don't want to run dry. It wouldn't shock me if you needed a top-up between changes @ 7500.

I recall that DOT 3 and DOT 4 are fully compatible as they are both glycol-based. It's DOT 5 you don't want to mess with.

Assuming that your stockpile is in sealed containers I'd say go for it. If the seal has been broken, atmospheric moisture will get in quickly and then it's no better than what has been in the car all along.

[1 Lucky Texan]

someone tell him what happens when you have a sidewall puncture on one tire of a matched set that are all at 40% tread remaining.

go ahead

tell him

[rasterman]

Originally Posted by 1 Lucky Texan

someone tell him what happens when you have a sidewall puncture on one tire of a matched set that are all at 40% tread remaining.

go ahead

tell him

Bonus points if there's a nonchalant shaving reference!

[MetroWestMA]

Everyone,

No matter if you have an AWD/4WD/FWD/RWD car you are a dumbass if you don't rotate the tires every 10K or so. They will last 60K and you can replace them at the same time because they will be worn out the same.

Also if your car starts pulling to one side, check the inflation and if that doesn't fix it you or your spouse probably hit a curb or hit a pothole. Get an alignment to fix it.

This is car ownership 101.

MW