2003 A6 3.0 Quattro vs 2004 A6 4.2 Quattro

[Vista461]

Looking at two A6's both with a little over 100, 000 miles.
One is a 2004 4.2 quattro the other is a 2003 3.0 quattro.
Having trouble deciding on one or the other. The 3.0 is $1000 less, but the 4.2 is a year newer.

Any thoughts on common issues with either or advantages one way or the other?


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[Sparkstack]

4.2 all day long.

[Vinnie981]

4.2 for sure.....i own a 2000 audi a6 4.2l v8 and a 2002 audi a6 3.0l v6............the 3.0 is problematic. plus the 4.2 has the widebody stance

[rollerton]

No question. I've owned a 3.0 , nothing against it but the 4.2 seems more reliable and better in almost every way.

The ONLY downside to the 4.2 is the economy / mileage. But, otherwise, no contest.

[Vista461]

We were leaning towards the 4.2, so its nice to hear that seems to be the better choice. Now just need a test drive .
Is the 4.2 realistically capable of mpg in the mid 20's on the highway?

[rollerton]

Is the 4.2 realistically capable of mpg in the mid 20's on the highway?

I own two of them...and from my experience only on the BEST day cruising at the speed limit, light foot no passing behind slow traffic. To be 100% realistic, expect just about 20mpg, slightly over if the engine is in good shape and tuned up.

[2.7taudi]

We were leaning towards the 4.2, so its nice to hear that seems to be the better choice. Now just need a test drive .
Is the 4.2 realistically capable of mpg in the mid 20's on the highway?

In don't think mid 20s is realistic for this vehicle. Maybe once or twice on long trips you may. But expect to average 17-20. That includes 3.0

Just about all c5 engines excluding s6 and rs6 average same mpg. The v6 are horrible on local but do quite well on strictly highway 25ish


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[8520]

4.2

To quote clarkson.

POOOWWWWWWERRRRRR

[Vista461]

4.2

To quote clarkson.

POOOWWWWWWERRRRRR

Lol.

Yeah assuming no issues with the testdrive and that the timing belt has been done at least once, I'm pretty sure we're going with the 4.2. It does look very cool with the flared wheel arches and such.

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[AQ6]

I've owned mine for 8 years used as my daily driver and check mileage at every fill up and I average 20mpg. Best was 24mpg on an all highway trip.
Good Luck

[Hambone101]

I had my 4.2 for 4 years and somewhere around 70k miles. Besides one wheel bearing, caliper, alternator and battery. The car was flawless for me. Keep up with the general maintenance and these engines are great. If you do a little searching, you'll find the transmissions are the weak point on these cars, mainly the tc seal going bad. As for economy, I averaged 17-19 in city driving and the best hwy I got was on a trip to fl from ct, doing an average mph of 80, I averaged 28mpg on the trip (using the trip odo and topping off at every gas station).

[mithril]

I own two of them...and from my experience only on the BEST day cruising at the speed limit, light foot no passing behind slow traffic. To be 100% realistic, expect just about 20mpg, slightly over if the engine is in good shape and tuned up.

Both of your's are S6's though, very different gearing from the 4.2L A6 so the fuel economy is worse ;) I regularly pulled 22 - 23mpg from my 2000 4.2L in 100% highway, 25mpg was not uncommon. 17 - 18 would be mixed city/hwy. The S6 sits about 1000rpm higher at highway cruising speeds which accounts for our lower mpg averages.

[Nogaro Nitwit]

My vote is 4.2

[rollerton]

Both of your's are S6's though, very different gearing from the 4.2L A6 so the fuel economy is worse ;) .

This is true! And honestly-- we've NEVER hit mid 20's on mileage on any trip of any length of any kind. With an old-lady foot I can barely break 20mpg, ....ever. So..."low" 20's seems achievable on the "normal" 4.2 ..but I'm still guessing you have to put some effort in to do it.
In town the very very best I can get is 13mpg...I apparently don't have the willpower to break 14mpg, but I think it's probably remotely possible. So, ..15-17mpg on the normal 4.2 seems reasonable, and I know that's really all you can expect from any 2.8 or 3.0.
4.2 wins. No contest.

[d6lc]

In my 173k mile 2001 4.2, driving normally I average 18 mpg over the last 11k and it's pretty consistent, worst was 14.4 and best was 22 which consisted of all highway at 70-80mph.

Averaging mid 20's in unrealistic dream in a 4.2 A6.

Be surprised if a 3.0 is significantly more efficient

[Scotty@Advanced]

A 6mt 4.2 will yield a combined in the low 20's. I get 17 in mine and 15-16in the S.

[aysix]

Both are slow =D

[PashaS4]

I had a D2 A8 4.2 and I got 24mpg driving to WA from UT, average speed was about 84mph

[Vista461]

I am actually suprised no one has said to get the 3.0. Is it that bad or is it just there isn't really a downside to the 4.2 when comparing the two?

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[JonMS]

There's almost nothing for "performance" available for the 3.0 and its "slow" hence the lack of popularity. I for one own a 3.0 AND a 4.2, I drive the 3.0 to work and enjoy the 4.2 on the weekends. The 3.0 in my eyes is not a slug as most on here see it as it has managed to give me car smiles every time I drive it. The 4.2 LOVE THE POWER and they really are solid engines when maintained. Gas mileage is also similar between the two, I manage ~20mpg city in the 3.0 and ~19mpg in the 4.2. As far as problems are concerned the 3.0 other then regular maintenance and a slight water issue, it has been a breeze to take care of and has never let me down(I've driven this thing across PA and back over 20 times without a hiccup). The 4.2 other then the transmission issues that we all know about and the paperwork I have on the car, it too has been rather easy to keep going albeit just a little more expensive for 2 more cylinders. /rant

[mithril]

This is true! And honestly-- we've NEVER hit mid 20's on mileage on any trip of any length of any kind. With an old-lady foot I can barely break 20mpg, ....ever. So..."low" 20's seems achievable on the "normal" 4.2 ..but I'm still guessing you have to put some effort in to do it.
In town the very very best I can get is 13mpg...I apparently don't have the willpower to break 14mpg, but I think it's probably remotely possible. So, ..15-17mpg on the normal 4.2 seems reasonable, and I know that's really all you can expect from any 2.8 or 3.0.
4.2 wins. No contest.

Define "effort" ;) My usual highway mileage is cruising up and down BC's high mountain passes at 140kph (87mph) to and from the BC interior. I averaged 27mpg on the one road trip we did from Vancouver to Seattle (ie. flat highway) in the A6.

[v8a6]

I vote 3.0.

The transmission in the 4.2 will blow up within max six months.... GUARANTEED!

[redneck truck]

Is this really a thread?! An M5 or a Sebring. Hmm, let me think.

[Vista461]

I vote 3.0.

The transmission in the 4.2 will blow up within max six months.... GUARANTEED!

Are trans issues through out the years? It seemed like most of the times I've seen a thread about a 4.2 trans problems they were mostly 2001-2.

[Vista461]

Is this really a thread?! An M5 or a Sebring. Hmm, let me think.

Lol.
I asked because I didn't know if one had more issues than the other. Also if the 3.0 got significantly more mpg than the 4.2 it may be worth the power trade off. That doesn't seem to be the case though.
I admit the 4.2 does have a better looking body, but the particular 3.0 I'm looking at has about15,000 less miles and is $1,000 cheaper.

But it sounds like besides the power deficit there are cam issues too.

[LINDW4LL]

3.0s blow. Get the 4.2 and call it a day. If you get the 3.0 you will regret it.

[v8a6]

Are trans issues through out the years? It seemed like most of the times I've seen a thread about a 4.2 trans problems they were mostly 2001-2.

History of my 4.2s

2000 A6 4.2 - purchased with 140,000 km. Transmission blew up within three months of ownership.
2001 A6 4.2 - purchased with 105,000 km. Transmission blew up within three months of ownership.
2002 S6 - 320,000km at dealer. Transmission DOA
2003 RS6 - purchased with 77,000km with TQ converter errors in the ECU

So, I got burnt twice on the first two A6's, then decided to start looking for cars with existing transmission issues. My feeling is that I would much rather pay less for one with a bad trans, and then do a 6speed swap, then to pay full price for one, only to have the trans explode within 90 days.

As for for the problems effecting certain years, my personal study shows a perfectly even spread from 00 to 03 :). However, I think some people will tell you that the facelift cars (02 and newer) had some issues fixed with the transmissions. I still would only buy one with a blown trans of 6speed swap.

In the end though, even with the transmission problems, the 4.2s are still my favorite car as a daily driver. Ill never give up my S6.

[Vinnie981]

I vote 3.0.

The transmission in the 4.2 will blow up within max six months.... GUARANTEED!

I have a 2002 Audi A6 3.0 and a 2000 Audi A6 4.2
And let me tell you that my 3.0 has the Code P0741 TCC Solenoid Stuck Off and has ruff downshift from 4th to 3rd while my 4.2 trans is still running strong 100% and has no issues. My 3.0 also had many other issues like both cats going bad, control arms, exhaust cam wiped(replaced), cam followers failed(replaced), plus many other things and in the end it threw a rod.

now let me tell you i 100% maintain my audis. the 3.slow and the 4.poo. But in the end the 4.2 has had less problems viewing the previous owners records and recipts and now my time with it.

you just need to maintain it. I am the second owner of this 4.2 and it had the TB job done at 37,000 miles and 75,000 by previous owner. I now have 82,000 on the dash. not to mention he also had the trans flushed at 37,000 and again at 75,000. So it was maintained.

[v8a6]

I have a 2002 Audi A6 3.0 and a 2000 Audi A6 4.2
And let me tell you that my 3.0 has the Code P0741 TCC Solenoid Stuck Off and has ruff downshift from 4th to 3rd while my 4.2 trans is still running strong 100% and has no issues. My 3.0 also had many other issues like both cats going bad, control arms, exhaust cam wiped(replaced), cam followers failed(replaced), plus many other things and in the end it threw a rod.

now let me tell you i 100% maintain my audis. the 3.slow and the 4.poo. But in the end the 4.2 has had less problems viewing the previous owners records and recipts and now my time with it.

you just need to maintain it. I am the second owner of this 4.2 and it had the TB job done at 37,000 miles and 75,000 by previous owner. I now have 82,000 on the dash. not to mention he also had the trans flushed at 37,000 and again at 75,000. So it was maintained.

When I said "I vote 3.0", it was a joke. Check my username :)

[Scotty@Advanced]

The transmission in the 4.2 will blow up within max six months.... GUARANTEED!

I've got an A6 4.2 with almost 180k on the original transmission, it came in running and driving. They can last a long time if properly maintained.. Problem is people don't do that.

[Vinnie981]

ok well i took it wrong.....im just trying to say that not all tip trans go quick. i know you have had bad luck with them and of course i know what you drive. you beemercer and countvohn are the ones who inspired me to get the 4.2l. and i dont regret it. I followed your builds on the AR

[v8a6]

I've got an A6 4.2 with almost 180k on the original transmission, it came in running and driving. They can last a long time if properly maintained.. Problem is people don't do that.

But you forgot to mention that you rebuilt enough failed ones to allow you to purchase a summer home in the Hamptons. LOL

OK, not to turn this into another 4.2 tranmission thread, but we all know that Audi says NOT to change the fluid in these transmissions, ever. According to them, it is a lifetime fluid. We also all know that that is BS, and has probably lead to the majority of the failures. That being said, I would not expect the average A6 4.2 owner to know that following Audi's recommendations will lead to eventual transmission failure. So, as far as the average owner is concerned, they ARE maintaining the car when they are not changing the transmission fluid every 50K (or whatever).

My point is that the majority of the C5 4.2 cars on the road have an auto transmission that will fail, or have already been replaced. I got burnt enough times that I will never buy a 4.2 based car again with a "good" transmission. There are enough of them around for $1500-$2000 with blown transmissions that are perfect candidates for a 6speed swap. And then you will never have to worry about the crappy tip again. Plus, the car just became a million times better with the 6speed. Where is the SWAP MAFIA when I need them!

And btw, the transmission in my 2001 lost reverse. Google it. It is a common failure. It happened at 105,000 (approx 65k miles) and had nothing to do with maintenance (Scott, please correct me if I am wrong). I think the issue was corrected in 02 and up. But if you go for a 00-01, have fun!

[Scotty@Advanced]

But you forgot to mention that you rebuilt enough failed ones to allow you to purchase a summer home in the Hamptons. LOL

I wish!

And btw, the transmission in my 2001 lost reverse. Google it. It is a common failure. It happened at 105,000 (approx 65k miles) and had nothing to do with maintenance (Scott, please correct me if I am wrong). I think the issue was corrected in 02 and up. But if you go for a 00-01, have fun!

It depends on exactly what caused reverse to crap out.. if it was clutch packs, then more than likely the fluid got old, nasty and water logged which caused the friction material to flake off. There is a weakness in the drum that houses the clutch packs but it fails pretty catastrophically taking out the trans case in some instances

[v8a6]

ok well i took it wrong.....im just trying to say that not all tip trans go quick. i know you have had bad luck with them and of course i know what you drive. you beemercer and countvohn are the ones who inspired me to get the 4.2l. and i dont regret it. I followed your builds on the AR

Nice. They are amazing cars once modded and dialed in. For my build, I pretty much just copied what Beemercer and CV had done, plus all the stuff that JHM had done on the B6/B7 S4 cars that were proven to make power with the 4.2.

[julex]

I agree... both are slooooow

[Vista461]

I agree... both are slooooow

Lol

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[Vista461]

Well not going to get that particular 4.2 A6. Has 125, 000 and unknown if or when the timing belt was done and price isn't cheap enough to buy it and do it right away.
Starting to look at some 2.7T Allroads now also.

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