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Have you ever wondered why there is enough space in the wheel-well of your car for a real spare tire but the manufacture has opted to short change you and has substituted a temporary or what is known as a compact spare instead?

You haven’t been short-changed, there is a reason and obviously it’s not to save space (these tires used to be called “space-savers”) as there is ample room around your compact spare tire to accommodate a real full size spare tire.

And it’s not to save money. If you were in the market to buy a new compact “temporary” tire (I have yet to meet someone who has) on average you’d be paying 20 to 30 per cent more due to the fact the tire manufacturer will build and sell thousand more regular tires to one space saver.

An example, one of the more popular sizes of tires can be bought for $114. The compact spare tire for the same vehicle costs $155.

Then it has to be weight, the less weight of a car, the better gas mileage it will get. That’s good reasoning except a space-saver isn’t all that far off the weight of a real rim and tire and isn't a big factor unless the spare is eliminated completely. This is the new trend that most automakers are following where 35 per cent (and climbing) of vehicles sold today do NOT have a spare tire. The backlash from consumers is now being challenged. Feeling the heat Honda has equipped all variants of the redesigned 2015 Fit with a spare tire after dropping the no-spare-tire feature on the previous model.

The most obvious reasons, saving space, better fuel economy, cheaper tires none of these are why you now have a compact “temporary” spare, it has to do with “shimmy.” “Shimmy” is the effect of tires not running in a pattern to which they were designed to run and causes the steering wheel to slightly vibrate back and forth.

If we go back in time, back to 1973 when automobile manufacturers swung away from installing the old style bias/belted tires in favour of the new radial ply tire. These new style tires were developed in the late ‘50s and into the ‘60s for jet airplanes that needed a superior handing tire for takeoff and landings. Radial tires were much like alternators and disc brakes, first for the airplane industry and now being fitted to automobiles.

Immediately the auto manufacturers were confronted with numerous customer complaints of a shimmy in the steering wheel and always after the vehicles tires had been rotated. The problem was simple, the owner or servicing garage wasn’t following the new way of rotating the tires of back to front and front to back and to NOT include the spare tire.

But that was contrary to the owner’s thinking, why not use the spare tire rather than to let it sit there doing nothing. Rather than follow the new way, the old way was used of Xing the tires for rotation. The spare to right rear, right rear to left front, left front to left rear and left rear to right front and everybody would be happy if it weren’t for the fact that this shimmy would occur. The spare was then included in tire rotation, regardless of what the owner’s manual said.

Radial tires when first installed and run in one direction and then changed and now spun in the opposite different direction ie. left rear spinning one way and now on the right front spinning the opposite way would create a shimmy.

The warranty claims were piling up something had to be done, thus the temporary or space-saver tire was created as a spare tire. The light bulb now on, owners and servicing garages adopted the new front to back, back to front that solved the shimmy problem once and for all.

One final item of why all the excess space when the compact spare is that much smaller? When a car is designed, it’s not only for the North American and European markets, it’s also for worldwide sales and distribution.

In some countries, especially the third world ones, the vehicles wouldn’t be bought if a regular spare tire was NOT sitting where it’s supposed to be, shimmy or no shimmy. Thus the bigger spare tire wheel well we all have .

First, it was VW, then Mitsubishi, now FIAT and make no mistake about it, the rest of the car industry is equally guilty of commonsense in the face of the fanaticism that prevails among the econazis., they just haven't been caught - yet!

What is going on and what should a poor car owner do?

The bureaucrats in the EPA and in Brussels looked up at the ceiling and in a moment of religious fervor, decided on the emissions levels that they wanted for carbon burning vehicles, never mind if they were achievable or not.

The engineers in the auto manufacturing groups knew instantly that these demands of purity could not possibly be achieved and many questioned the assumption that their petrol burning creations were even responsible for the the climate change that many doubted even existed, or had even been proven to a decent level of engineering credibility.

(There are so many well documented scandals concerning the way that beholden so-called scientists have fudged the figures on global temperature change that their credibility is in tatters.)

So what did all these practical engineers do?

They manipulated their engine management software to give the fanatics what they think they wanted, at the same time giving the car owner a car that was not only a lively, responsive thing to drive, but one that produced spectacular increases in fuel economy.

They should all be awarded a medal for practical commonsense in the face of stupid bureaucratic meddling.

So what now?

It all depends on what you get offered.
If you cannot re-licence your car until the software has been modified, you're screwed and your car will never feel the same again. Both from a driveability point of view or that of fuel economy.

The last thing you want to do is go anywhere a dealership that insists on changing your engine management soft ware.

If you get offered a cash payment with no strings attached, take it and be happy.

If you get offered a buy back, it will be at the depreciated, used car value, and not what you paid when the car was new. In this case it comes down to a financial calculation rather than one which directly concerns the vehicle.

The bottom line is:


Other blogs worth reading

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44) Future shock, the unending complication of electronic devices in you car.

47)  The case for annual safety inspections.

51) The piston engine is going to be with us for a very, very long time.

52) Avoiding rip offs in the car repair business.

58) Electronic brake force distribution.

61) Hydrogen vs electricity - no contest.

63) Why flushing brake oil makes sense.

64) When should I change my oil?

66) W/W antifreeze and long term warranties.

67) Nitrogen

68) Recirc A/C

70) Electric car radiation danger

71) Fuel saving devices that don't

75) Scheduling appointments.

78 Modern design of alternators and batteries.