Does Avalon Need Premium Gas

Actually all 3 cars are worth considering. Ford is cheapest, Toyota most reliable, Chrysler coolest. Depends what you want.

I tend to agree with the post labelling the Avalon as most reliable, 500 the cheapest and 300 the coolest. I compared the Avalon to the 500, and I believe the Avalon is marginally larger (length, wheelbase, weight). I have to agree that the new Ford 500 and its Mercury sibling look fine. The Avalon hardly has what one post called "old technology": New engine, all new body, more standard equipment. It is a greatly improved and refined vehicle compared to the earlier Avalons ...and its performance rivals the 300C in most respects.

I, too, would be surprised at any head-to-head review that did not name the Avalon as best of this trio. The only complaint I hear is about a relatively small trunk.

I doubt that the the difference in reliability is significant. If forced to rate them I'd go Toyota, Ford, Chrysler, although my personal experience has been Ford, Toyota, Chrysler. $5000 will fix a lot of problems. The Toyota drive train design is the oldest and most stable, so that is an advantage. However, the Ford design is not "all new" but based largely on an existing Volvo platform. Likewise, the Chrysler design is based on an old MD platform. All three are now assembled in the US (if not form US parts).

Ed

Well, lessee now, inasmuch as it's true then I do indeed mean it...what's your point Allen?

Well, I must admit that I don't get the joke that you seem to be chortling over...wanna clue me in?...

The Toyota Avensis (almost the equivalent of the Avalon) diesels are now the taxi vehicle of choice in most cities here, by far and away ahead of any other make or model.

The reason is simple: extremely reliable, easy to fix if they do go wrong, and the diesel and petrol engines give approximately the same power and feel the same (especially when driven at full power approximately six inches from the car in front, which is standard driving for most taxis round here!).

Ok. Sure. Without detonation, your car won't move. That's what makes engines go. You may have meant premature detonation or pre-ignition. But you did say "prevent detonation".

In my car, the high octane fuel detonates better than the lower octane grades. Fortunately for me, it doesn't PREVENT DETONATION.

American Heritage: detonation (dµt?n-³?sh?n) n. 1. The act of exploding. 2. An explosion.

Of course I did and I meant detonation too.

Gary, son, the jokes on you. Detonation isn't normal combustion

During combustion in an internal combustion engine the flame front is many many times slower than detonation.

Actually, in detonation, there's no defined flame-front at all because all of a relatively small area of the chambre ignites 'all at once'. That's why it's called 'detonation' you see.

You need to read up on these engine terms before you embarrass yourself in public like this again.

I wasn't as hard on you as I could have been because I realize that you may not have a lot of experience with engines and are still young enough to brashly lash out (in public) even though you're not sure of yourself. Be careful son, you'll get a reputation.

That's pretty funny Gary...read my explanation of your faux pas up stream...I almost feel sorry for you when you realize your error...especially if you have any mechanic friends.

Detonation jokes aside, it *is* rocket science.

Compression radio is only the dumbed-down story of what is going on. Proof? Compression radio doesn't change but with too low of an octane rating an engine will knock under heavier loads. A very important factor is the peak cylinder pressure.

My 2000 Avalon 3.0L engine has a 10.5:1 compression ratio. In classic terms thats well into premium fuel range. In modern engine practice its quite comfortable with 87 octane rating. Lesser engines such as the 3.0L Nissan was using in 2000, can not adjust so 91 octane rating is spelled out in no uncertain terms in the Nissan owners manuals.

With the relatively high compression ratio and ability to control mixture, timing, and intake valves, Toyota is able to operate at optimal cylinder pressure for maximum efficiency. What others have missed in my prior post was the observation there is no assurance of *energy content* in gasoline. Just because 93 octane rating will permit higher cylinder pressures doesn't mean the 93 octane rating fuel has as much energy content as the 87 octane rating fuel. Without the energy it won't go faster, it won't produce the MPG. This is why alcohol in gasoline is a bad idea, alcohol has "octane rating" but lacks the energy of real octane.

What matters is the sum total efficiency. Optimizing one variable based on "more octane rating is better" is a fool's pastime.

Repeating what I said earlier, in many tanks of 93 octane rating I could not measure any improvement. +0.5 MPG is the most I could wishful guess from the numbers, while +-1.0 MPG is common tank to tank variance.

Those who have replied have also missed my point about the ECU retuning itself for conditions. Just because it "feels" peppier doesn't mean it really is.

Of course David, nothing in this post fails to agree with what I said...you did infer that the ecu and spark retard (through the knock sensor) will prevent damaging detonation but at the expense of HP. My point is that (as I said) if you DO NOT HAVE the compression ratio to require high octane fuel then you're wasting your money on it. As a matter of fact, the higher the octane rating then the LESS energy the fuel actually has. You cannot allow your engine to detonate (despite what Burnore thinks!) because it will wreck it...so in the modern engine the knock sensor will retard the spark (thus reducing the charge pressure and preventing detonation), this also reduces HP and fuel economy.

A few years ago I used to be employed in the Canadian Air Force as an Argus Flight Engineer. We had the complete operation of four large piston engines (3700 BHP) to look after. I recall one trip between England and Canada just before Christmas one year, we were on climb-out from Keflavik Iceland on the last leg of our trip.

Right after take-off when the pilot called for METO (climb) power and as the water injection was shut off, number three engine fuel flow DID NOT increase from 1800 PPH to 2400 PPH as it should have, seconds later the torque dropped quite a lot and the cylinder head temp on that engine started climbing rapidly...by the time I got it shut down it was producing almost no torque and the temp was off the clock. We then did something slightly illegal (flew home - it *was* Christmas after all, who wants to spend it in Iceland?).

I followed up on that engine and found on teardown that it was wrecked by detonation...large holes through most of the 18 cylinders, several valves broken off etc. (and in only several seconds too!)

Detonation is fearsome on large delicate engines, it does a job on them, believe me...

BTW, we don't use the euro, and prices here for vehicles have changed very little.

Also the Avalon trunk cannot be expanded with fold down seats, I believe. Only a small area in the middle folds down for skinny items.

The rear seats of the "Five Hundred" fold down, but not flat. It is more Camry like in that a large round hole is available. It looks like it would be perfect for a bag of golf clubs, but nothing more. You could not put a big box in the back through the opening. I looked at the "Five Hundred" and it seemed OK, but the seats were not very comfortable.

Art wrote:

Not to speak of the fact that the 500's styling is a shameless rip-off of the Camry. Look at the back end of both.

------------------------------------------------ The DNC - Building a bridge to the 20th Century.

Who cares what the reviewers think. I'm starting to think that they don't even bother driving the cars, they just reprint the press releases. A few weeks ago, I went out and test drove both a new Ford Five Hundred and a new Avalon. Here's my review. We have a two year old Avalon and we love it. My wife drives it every day and we love to take it on long trips. It's silky smooth and big and quiet and comfortable. Because of that, we overlook that it's pretty homely, wanders a bit down the freeway and sort of plows around sharp turns.

I was looking for a new car for myself and was rather interested in the new Avalon. The dealer just gave me the keys and said try it out for a day or two. The new Avalon is no longer silky smooth. It now has more HP and it's got a bit of a growl and a shake to the engine. The extra Hp means it now has torque steer. Not much, but noticable. The new one handles better, no longer wanders and corners better. It also now thumps over potholes and has tire roar. The old one is silent. The new one even got a loud resonance rattle going in the passenger side door panel on a rough part of the freeway. The new Avalon no longer feels like a Toyota, but more like a really big Honda Accord. The new Avalon interior is higher styled, but stupid. There is now a garage door over the radio so you can either lift it everytime you want to play with the radio and heat or you can leave it sort of open because it doesn't retract all the way. The door hangs out about an inch so that you have to look around it to see what you are adjusting. The center console is now wider causing one to wonder why a front wheel car needs a big stupid console down the middle and it has wood trim on it right where your knee hits. Over and over and over. Ouch. The wood trim was really ugly yellow. The car now comes in four fixed option packages that give you the wrong options no matter how much you pay. We are definately keeping our old Avalon.

A car loving buddy and I tried out a Ford Five Hundred. All wheel drive, leather, CV transmission. We liked it. First, you sit up a little higher and the all around visibility is wonderful. We each though that the seats were about the best ever. Avalon seats are good, but they have no support at all. The back seats of both the Avalon and the Ford are excellent. The Ford has the better trunk. The Ford instruments are big and easy to read. All the knobs are handy and easy to adjust like on the old Avalon. The new Avalon is getting bottonitis like the German cars. The Ford felt more rigid. No rattles, groans, vibrations. No road roar but a slight bit of road rumble over the section of freeway that made the Avalons panels rattle. Both cars handle just fine for every day use. the Ford is taller and at the limit it feels a little tippy at about the same time that the new Avalon starts to plough. The Ford doesn't accellerate as fast as the new Avalon, but it's faster than the old Avalon. I was perfectly happy with the old Avalon. The old Avalon's transmission is sort of clumsey. The new ones' is excellent. The Ford CVT is a kick. Stomp it and the engine goes to red line and the power is right now. Along with the engine noise which I rather liked. It's a good noise. Neither car is ugly, but neither car is beautiful.

The Ford with all the stuff was about $28,000 and the dealer was offering a two grand discount. The Avalon was packed with crap that I didn't want like hold the stupid button down for three seconds to shut it off and auto locking doors that you are never sure are locked and for about $36,000 with a couple of thousand worth of extra dealer profit.

That's $26,000 for the Ford and $38,000 for the Avalon. If I could get a base Avalon with leather (which you can't) for $28,000, I might pick it over the Ford just because it's a Toyota. But way down deep, I think that the Ford is the slightly better car. Dennis

On Mon, 04 Apr 2005 17:14:13 -0400, snipped-for-privacy@mailcity.com wrote:

WHAT IS YOU RPROBLEM?? THJIS IS A NISSAN GROUP, TAKE TOYOTA SH*T TO TOYOTA LAME NEWSGROUP, THAT COMPANY IS OCVERPRICED AND ENGINES NO COMPARIOSN TO NISSAN, WHAT MAKES PEOPLE BUY THEM IS THE BODY/EXTERIOR DESIGN AND RELIABILITY FAME COMING OFF 1970-1987, IT'S NO LONGER, MANY OTHERS ARE BETTER AND MOST IMPORTANT CHEAPER THAN TOYOTA.

ALSO AVALON IS A TYPICAL SUV-LIKE GUZZLER, if you lik epolluting air go to Toyota groups.

But I like Ford, support American jobs