6 cylinders versus 4 (longevity)

We’ll looking at buying a new Audi A4. We also tend to keep cars forever (VW Golf for 11 years, Sienna van for 12 and counting). My wife and I disagree on whether spending extra money on the 6 cylinder version translates in the engine lasting longer (the logic that a 6 cylinder doesn’t work as hard over time). Is that a valid belief?

A 6 cylinder can last just as long as a 4 cylinder and vise versa. The number of cylinders has absolutely no bearing on longevity. Maintenance habits, driving habits, manufacture quality and environmental conditions are the factors that determine longevity, not the size of the engine.

The 6 cylinder option costs more NOT because it is higher quality. The 6 cylinder costs more to manufacture and it is considered a luxury which provides more power/performance.

Spend the extra money for more power and a little smoother running engine, but longevity will be about the same. Other factors are more important than 4 vs 6.

Keep in mind that the 6 will (all else being the same) be a little more costly for maintenance and will have about 20% more moving parts to fail.

I believe the overall cost of ownership will be less with the four cylinder, especially if you add in the cost of fuel.

I suspect that far more cars end their life due to neglect, accident, rust or an accumulated non-engine related issues than due to engine failure.

No, it isn’t a valid belief. A properly maintained four cylinder car can last just as long as a properly maintained six cylinder car. The things that lead to the demise of a properly maintained car are not related to the number of cylinders. I am thinking of things like oil deprivation, overheating, and failure of a major component that isn’t worth fixing because of the depleated value of the car, like the transmission.

I have to disagree with the previous comments but only in this respect…
If your vehicle is going to be subject to harder use ie. trailor towing or high weight applications.
If for some reason, you have to work at or near the performance limits of a 4 cly…by the same manufacturer, than yes, the 6 cyl. would give you better service.
In the military, when ordering vehicles from civilian suppliers, that was always a primary consideration. But…a 4 cyl within it’s design limitations vs a 6 cyl within it’s…a general agreement of NO difference.

So what it’s general use will entail is of concern and a determining factor in my experience.

Good post! In Germany, where you are allowed to drive 100 mph, the extra power might come in handy, as it would with towing a trailer. Under normal driving with the very low US speed limits, I beleve a 4 cylinder will be much less expensive to won over its life. I specified a number of cars for arctic use, and we always selected the smallest engine, since quick warmup and the lack of high speed roads made the 4 cylinder models more reliable and LONGER LIVED.

Think of it as assigning a star athlete to work in an office and not allowing him to excercise! He won’t live as long as the 110 lb secretary. Long life has very little to do with how STRONG you are.

I would strongly recommned the 4 cylinder model, it will save you a great deal over the long run.

It should be mentioned that the 4 banger in the A4 is a turbo, Whilst the V6 is normally aspirated, that needs to be taken into consideration

As I was reading the thread, I had the same caveat in mind with regard to situations where they stuff a dinky engine into a large vehicle in a sometimes misguided attempt to advertise better gas mileage. As one example, there have been heavy vans outfitted with dinky 4 cylinder engines that are laboring quite hard to move that mass around. The consumer only looks at the mileage claims. Not only is the engine laboring, the gas pedal is 3/4 of the way to the floor, eating into that mpg margin.

You guys seem to believe that working an engine harder has nothing to do with long life. A 4 cylinder has to turn more revolutions in a life time and is under more strain most of the time. It only make sence that a good 6 cylinder will last longer.

Let it be said that, as FoDaddy says below, the 4cyl model is turbo charged, which will require more strict maintenance than a normal 4cyl. Keep in mind Premium fuel is recommended for both engines, and you’ll most certainly NEED it in the turbo engine
Turbo 4cyl:
211 HP @ 5300-6000 RPMs
258 ft-lbs torque @ 1500-4200 RPMs
21/27 city/highway 23 combined

NA 6cyl:
265 HP @ 6500 RPMs
243 ft-lbs torque @ 3000-5000 RPMs
17/26 city/highway 20 combined

Many four cylinder engines are designed to work at high RPMs, yet they still last for 200,000 miles or more. Besides, a four cylinder car also has less weight to push down the road, so it has proportionally less work to do.

A four cylinder engine doesn’t necessarily need to work any harder than a heavier six cylinder engine. The assumption that it does is problematic.

I was pointing out that the 4 cylinder in the A4 is turbocharged which means the engine is literally under more pressure than the normally-aspirated V6. While turbo durability is much better than it used to be. It’s a very expensive piece of moving machinery added to the engine. Which is one more thing to fail.

That’s a good point, although I wonder if adding the turbo adds to the fuel efficiency or just adds power. I also wonder if the turbo would be any different if it was designed to add efficiency.

When buying a German car I (having grown up in Germany) would always go with a specification that is as close as possible to the volume models over there. How is it that just today a German technical institute that does the roadworthiness evaluation of every car every 2 years came out with a report that BMW, Audi and Volkswagen even beat Toyota in Honda in “failures” and that German cars have a bad reliability reputation here? Because in America we like to order these models in configurations that are nusual for Europe and hence not as refined quality-wise.

  • Passat 4-Cyl 2WD Diesel with stick shift: bulletproof
  • Passat 6-Cyl with AWD & Automatic: nightmare
  • BMW 525i: Toyota-like reliability for many model years
  • BMW 540i: nightmare

I just checked the Consumer Reports reliablity prediction for the A4, comparing the 4-Cyl to the 6-Cyl. The 4-Cyl’s and the 6-Cyls “expected reliability” for minor or major engine problems hover both around “slightly better than average” and “much better than average”. Overall the two rate fairly simlar with the 4-Cyl being slightly better. Interesting if you atke a detailed look at the stats: The 6-Cyl report lower “Drive System” Reliability (still average but not above like the 4-Cyl). I would assume that this is the case because the more powerful 6-Cyl can potentially put more stress on the drive system. Interestingly enough the stats for the transmission do not vary (although the 4-Cyl’s still is still a little ahead when it comes to reliablty).

Take these statistics with a grain of salt but they may give you a few pointers. Bottom line: Can’t go wrong with any of them. Which makes - with the optons being equal - us take a look at www.fueleconomy.gov. There, the 2008 4-Cyl gets a combined fuel economy of 24 MPG while the 6-Cyl gets 21.

Keep us posted what your decision is!

So, you don’t think a 120# man has to work any harder that a 200# man carrying a 150# man down the street?

The Audi, by itself, will be a high-cost automobile…ANYTHING turbocharged will multiply those costs…Your desire to own an Audi will not last 10 years, so go with the 6 which should have much better resale value…The light that burns twice as bright only burns half as long…

“The assumption that it does is probleematic” only to you!!

Of course you would also need a crystal ball where fuel prices go. If it stays where it is right now who cares if the thing gets 21 or 24 MPG and resale value of the 6-Cyl gets higher. The higher fuel prices go in the next 10 years you plan to own this vehicle, the more attractive small, turbocharged engines will become and the resale value proposition would be upside down (look what happened to SUVs in the last 6 months or so). In Europe, where gas is upwards of 8$ per gallon, the majortity would not even think of getting the 6-Cyl, because if you spend $ 130 to fill up your A4 it sure matters if those 130$ take you 345 miles (6-Cyl) or 395 miles (4-Cyl). If you spend 35$ for the same tank of gas at current gas prices in the US: who cares.

I don’t think you adequatly explained anything. REALLY NOW, just how much weight are we talkin’ about?? You could insist that no one ride with you, that would lessen the weight.

I don’t think a 3,000 pound car will notice the 70 extra pounds, especially if the car’s weight capacity isn’t exceeded. As long as you stay within the design limits and you properly maintain the car, that extra 70 pounds won’t make a bit of difference in longevity.

NEWS FLASH: Cars are not the same as people.