Shoot2Thrill

The following is opinion but it might just be true:

The TL uses premium fuel because:

Surveys of the public said that people perceive a luxury car to require premium fuel. Thus, look at the 240HP 3.0L Honda V6 that uses regular. It has lower compression than the TL. Yet, if you extrapolate the 3.0 to a larger displacement 3.2 the horsepower would be approximately 256HP. If you bump it to 3.5 the HP would be approximately 280HP.
You can play with the numbers from other Honda V6 engines but it safe to say Honda could have put an off the shelf engine in the TL that was used regular fuel and achieved the same power. Thus, because a marketing decision was made to use high compression rather than displacement the TL will cost and extra $1,000 or so in fuel cost per 100,000 miles. Not a fortune but not necessary it an overall technical sense.

1GreyTeg

I'm shooting from the hip here but can anyone show the HP ant TQ curves of both motors you are attempting to compare? And or overlay them to examine performance and or response?

It is possible that Peak HP and TQ numbers alone do not show the whole story when comparing the two, but more how and where the power is delivered and or how it actually feels, IE entry level luxo sports sedan in direct competition with the BMW 3 series. H'mmm competition couldn't be more fierce. And for the ULEV2 rating and admirable MPG I think this particular market segment will take the .30 more per gallon or whatever it is as a trade off.

Also, what would the weight difference be? Power to weight ratio plays strongly in the performance catagory.

and finally, you do see who the TL is marketed to? If not, take a look at just about every commercial between F1 segments this weekend. Especially since it's in England this round.

Brettg

Bigger engines are nice, more power, and more tourqe.
Unfortunetly, they are heavier, use a lot more fuel, take up more space under the hood, and produce more polution.

Brett

SouthernBoy

Larger engines do not necessarily produce more pollution nor do they necessarily use more fuel.

Example. My 1988 Mustang LX 302 CID (that's 5.0 liters for you liter lovers) was 4 times cleaner burning than my wife's 1991 Honda Accord LX with less than half the cubic inches. Plus it managed close to 26 MPG on the road... after bolt-on modifications and a rear end gear change to lower gears (3.55's from 3.08's). Granted, Ford's EEC-IV ECU was far better than Hondas system, but still that's pretty impressive.

And check out the MPG of the new Corvettes. The small block Chevy just keeps getting better. And my TL manages 32 MPG at 62 MPH in the summer with the A/C on. Not too bad, I'd say.

And as gearheads, who cares anyway. We want power and performance. Fuel economy and low emissions take a back seat to those two goals.

SouthernBoy

As for octane requirements of a given engine in a given state of tune, there are too many variables here. Mechanical compression ratio, ignition timing, combustion chamber design, camshaft timing and profile.. just to name a few.

Bottom line.. if your car's manual calls for premium, use it. If it happens to call for 87 octane, use it.

Shoot2Thrill

That was not the point.

SouthernBoy

To Shoot2Thrill;

You're right.. my mistake.

A good point was raised. But frankly, I would like to see the TL have a larger engine.. say around 220+ cubic inches and stay in the same comparable state of tune. That should result in around 300 - 310 horsepower and around 280 - 285 lb/ft of torque.

jkayca

I think 270hp on a fwd car is already too much. With over 300 I think the TL would have to be changed to a rwd or awd setup.

crazymjb

More displacement = more weight. Its worth the 1k in fuel IMO. For the average person they are spending well under a buck a day on the fuel difference. As far as using lower octane, shouldn't be done on a car with a compression ratio of 11:1, unless you want to try to run it as a diesel.

No more power to the front wheels. I would like it to be a 4+L V8 with AWD.

Brettg

All wheel drive takes up a lot of space, adds a lot of weight, robs power.

Now a car like theTL could be all wheel drive and have a 5.0L engine,
but you would have no back seat or trunk, or gas tank, something would have to
give someplace....

I really dislike all wheel drive in cars, rwd is not great in the snow.

I like the TL just as it is engine and chassis wise, they could learn a lot on
control, display, and driver aids from VW though...

Brett

DEG

11:1 compression ratio needs higher octane to reduce pre-ignition (pinging) by burning slower.

Pure Adrenaline

iTrader: (2)

Opinions are like assholes; everyone has one. Let's hear what you have to say.

This is ridiculous. Please provide the source(s).

Sorry, but that's not how you make/calculate horsepower. Displacement is a factor, yes, but you just can't do it that way.

Possible. It is basically an off-the-shelf engine. The J-series family shares a lot of components together. The TL engine is just more sophisticated and tuned to perform better.

Engineers don't wake up in the morning and say, "Damn, I feel like requiring premium fuel in the TL today." Try running 87 octane and log the mileage. If you can, hook it up to a scanner and log the knock sensor readings, too.

My dad's 55,000-dollar luxury vehicle doesn't require premium fuel. The engineers did away with regular, so they didn't require the higher grade.

Most luxury vehicles need premium fuel because their engines are much more sophisticated, and of course, luxury vehicles must have the higher horesepower to match the image. Therefore, engines are tuned to perform better which, in most cases, require the higher detonation point in the premium fuel.

I'm sorry, but your theory is the most ridiculous and absurd thing I've ever heard. A marketing decision? Increased maintenance costs on purpose? I'm sorry, but when the beancounters work day and night to shave 3 pennies off the cost of producing a fender, they don't negate those efforts by telling people that it costs more to own and maintain the car, thus turning away potential customers.

massr1

mrbrett

Generally when you use higher octane fuel, you will acheive slightly better gas mileage... I would assume that the cost difference would be minimal, to that of regular unleaded factoring in the mpg... Complaining about the gas situation is this country is retarded anyway... its not like we can do anything about it. Gas prices will continue to climb, and we will continue to purchase fuel for our vehicles, until they invent something far superior, people will continue to buy vehicles that burn fossil fuels...

As far as requiring the higher octane fuel... take my word for it, it is neccessary. I had a RSX type S before I bought my TL. I let someone fuel it up for me and he put in a tank of regular on accident, boy did my car run like shit... It was noticeable slower, a little hesitant at taking off and it pinged like crazy...

ayethetiense

Yup, why do you think the 300hp higher torque RL is slower then the TL

crazymjb

All wheel drive does not HAVE to take up a ton of space and add a ton of weight. In fact adding a system to a car adds about as much weight as throwing out your passenger. THe Evo and STi do much better than the TL and both have AWD. Through Turbo or Super acura could make the neccesary power to drive an awd unit without adding much more weight. Take a look at the Evo IX which is gonna launch sometime soon. Also take a look at saabs, my friends 9kAero will put down 258Pound feet off a 2.3 litre, and the newer ones do even better. AWD can not only improve handling but improve launch times, more rubber on the road providing power.

2003 Acura TLS260-Silver

Let's face it. If your going to buy a high powered sports or luxury car, your operating costs are going to be higher than normal. Expect to pay premium fuel costs for the luxury/sports ride. Expensive replacement parts will also be reflected with a premium priced vehicles. I don't know of any pure sports/luxury rides that don't use premium fuel. For peeps bitching about premium fuel costs, then trade in your ride for a Honda Civic, Suzuki Swift, Mini, Yugo, walk for pete's sake and don't own/lease a car.

Michael03TLS

Pure Adrenaline

Pure Adrenaline

iTrader: (2)

Umm, reading your responses, I think we're on the same page. I think you misunderstood me.

Pure Adrenaline

iTrader: (2)

Yes, I stated that displacement is a factor in producing horsepower, but I was just informing him that you can't extrapolate theoretical horsepower ratings that simply.


Isn't this a re-wording of what I said? I said J-series family engines share a lot of the components together, and the Acuras have the more sophisticated and better tuned versions.

Once again, exactly what I said.

You're talking like the car requires premium but my father put in regular. Let me clarify it for you one more time. The car does not require premium. And yes, the engine is perfectly fine. He HAS been putting regular gas in it, and he hasn't done any damage, because it only requires regular. He drives at low and high speeds. Why is this a load of bullshit? By the way, it's a 2004 Yukon XL Denali.

higher octane fuel prevents pre-ignition in the combustion chamber to prevent pinging What do you think I meant by "they need the higher detonation point of the higher grade fuel"?

You're rewording everything I said, then saying that it's a load of bullshit.

angler67

Ridiculous? Absurd?, hardly. If you think so you do not understand how marketing works in our world. Image is everything.

The bean counters want to save on production costs which improves profits. They do not give a rat's ass about customer costs (look at inflated maintenance costs, where dealers really make their $$$) especially on luxury targeted items.

Engineers do not develop in a vacuum, they get requirement specs from the company which usually includes executive mgmt from engineering, sales and marketing.

It is very possible that such a requirement was dictated to the final packaging of the product.

Shoot2Thrill

Expect to pay premium fuel costs for the luxury/sports ride. Expensive replacement parts will also be reflected with a premium priced vehicles.
Perception like that is the point!

Pure Adrenaline

iTrader: (2)

I'm not a simpleton when it comes to business/management/marketing. I do understand how marketing works, and being where I am from, I know exactly how "image is everything", although I despise that concept.

Yes, they work to reduce production costs, therefore improving profits. This is, in part, in an effort to offer the car to the consumers at the lowest cost possible. But they aren't going to turn around and say "oh, this car only requires premium; it costs more to own this car." To me, that negates the effort to reduce production costs which usually has the goal of offering the product to the consumer at the lowest price possible.

Since when is pumping premium at the gas station the cool thing? Since when does the concept of "image is everything" factor into pumping gas? Are people THAT shallow? "Oh, my car requires premium, but yours only runs on regular. My car's better, so I'm better than you."

This is how Mercedes Benz used to R&D their vehicles, and they failed. "Here are the specs to which you must build this car, at or under this cost, to achieve these sales, and to fit this image and the demographic. The fact that world's one of the most renown car companies tried this method, failed, and realized their mistake, therefore drastically restructuring their R&D process says something.

Well, I just refuse to believe that people are so shallow to the point that car companies must unnecessarily require premium to sell cars.

Like I said before, run 87 in your car. Log the fuel mileage, and the knock sensor readings. End of story. Engineers won this round, not the marketing executives.

MR1

Glad you have such a good grasp on things. Here are a couple of facts.

1. For model year 2002 and 2003 perhaps longer the Honda Pilot specified Regular and the Acura MDX specified Premium for the same 3.5L engine with the same quoted horsepower.

2. A few years ago Mercedes let engineers design the cars and cost be dammed. Prices went through the roof and sales to the basement. Sales and marketing and manufacturing now have much greater input.

Les C.

Pure Adrenaline

iTrader: (2)

Hi.

For 2003:

Honda Pilot
-3,470 cc 3.5 liters 6 V front engine with 89 mm bore, 93 mm stroke, 10 compression ratio, overhead cam, variable valve timing/camshaft and four valves per cylinder
-Unleaded fuel
-Fuel economy EPA highway (l/100km): 10.7
-Multi-point injection fuel system
-Main 73 liter unleaded fuel tank
-Power: SAE and 179 kW , 240 HP @ 5,400 rpm; 242 ft lb , 328 Nm @ 4,500 rpm

Acura MDX:
-3,471 cc 3.5 liters V 6 front engine with 89 mm bore, 93 mm stroke, 10 compression ratio, overhead cam, variable valve timing/camshaft and four valves per cylinder
-Premium unleaded fuel
-Fuel economy EPA highway (mpg): 23 and EPA city (mpg): 17
-Multi-point injection fuel system
-19.2 gallon main premium unleaded fuel tank
-Power: 194 kW , 260 HP SAE @ 5,750 rpm; 250 ft lb , 339 Nm @ 3,500 rpm





For 2004:

Honda Pilot:
-3,470 cc 3.5 liters V 6 front engine with 89 mm bore, 93 mm stroke, 10 compression ratio, overhead cam, variable valve timing/camshaft and four valves per cylinder
-Unleaded fuel
-Fuel economy EPA highway (mpg): 22 and EPA city (mpg): 17
-Multi-point injection fuel system
-19.2 gallon main unleaded fuel tank
-Power: 179 kW , 240 HP SAE @ 5,400 rpm; 242 ft lb , 328 Nm @ 4,500 rpm

Acura MDX:
-3,474 cc 3.5 liters V 6 front engine with 89 mm bore, 93 mm stroke, 10 compression ratio, overhead cam, variable valve timing/camshaft and four valves per cylinder
-Premium unleaded fuel
-Fuel economy EPA highway (mpg): 23 and EPA city (mpg): 17
-Multi-point injection fuel system
-19.2 gallon main premium unleaded fuel tank
-Power: 198 kW , 265 HP SAE @ 5,750 rpm; 253 ft lb , 343 Nm @ 3,500 rpm

Notice the displacement differences, grade of fuel required, and the power ratings.

Again, let's reiterate what I've said.

1. J-series family engines share a lot of components together -- check. They are virtually the same engines.
2. Acura engines are tuned to perform at a higher level, thus requiring the higher detonation point of the premium fuel -- check. Acura engines have slightly higher displacements (notice the Pilot's engine remained the same, while the MDX gained a little, although negligible, displacement. And since they are virtually the same engines, the only major difference is the the grade fuel required, due to the engine tuning. This is why you can't swap an MDX ECU with the Pilot ECU. Just like Honda Accord and the TL, they may be from the same engine family, but they are differently tuned.

Again, just like the other guy, thanks for rewording what I said and calling BS.

Next thing I know, you'll be trying to tell me that Honda engines run on hamsters.

Pure Adrenaline

iTrader: (2)

Oh, by the way, I'm glad YOU have such a good grasp on things. There was no 2002 Honda Pilot. kthxbye.

afici0nad0

but why are most luxury vehicles' engines much more sophisticated? is it because, based on the price, buyers are expecting more sophistication from their engines? if so, are marketing departments fully aware of this consumer behaviour? and if so, is this why premium fuel is recommended in luxury cars?

if luxury vehicles must have higher horsepower to match their images, wouldn't this type of decision be based more on marketing than, say, performance?

i don't have any answers, i'm just throwing out questions...

Pure Adrenaline

iTrader: (2)

I'll use the MDX vs. Pilot example here.

When I say the Acura engine is more sophisticated, I don't mean forged crankshaft, piston rods, etc. Remember I said that these engines are from the same engine family, and they are virtually the same engines as far as the architecture and the structure are concerned.

Yes, it is true that the luxury counterpart (MDX) of the mainstream car (Pilot) should have the luxury, and the extra horsepower to boot. The main difference, and the same difference that requires premium fuel, is the tuning. For instance, by requiring the higer grade fuel and utilizing its higher detonation point, the engine can be run on more advanced ignition timing to increase the horsepower and torque output. And you can also achieve higher fuel mileage with premium fuel, as the stats indicate above.

So the bottom line, it is a marketing decision to provide the luxury and the increased horsepower output in the luxury counterpart of the mainstream vehicle. People want the increased horsepower when they are buying the more upscale version of a certain car. This is the same reason why GM advertised the F-body LS1 horsepower rating lower than the Corvette's rating, when the engines are virtually identical. On dynomometers, F-body LS1 is putting down near identical numbers as the Corvette.

However, what these guys are telling me is that Acura is requiring premium fuel for no good reason other than the image of how a luxury car should use premium fuel whereas they require regular grade fuel in Honda vehicles. Requiring premiuim fuel in Acuras, but regular fuel in Hondas is NOT an image thing. Our Acura engines NEED it to achieve the higher horsepower and torque output.

afici0nad0

good point...

i think the thread originator did say that the reason why premium fuel is recommended in luxury cars is because of consumer preference.

but i couldn't find anywhere saying it was the only reason.

hype debate...

afici0nad0

premium fuel is recommended in highly tuned engines. it just so happens that more cars in the acura line-up are equipped with highly tuned engines, compared to the honda line-up of vehicles.

the decision to drop a highly tuned engine in an acura is marketing-based, but the decision to recommend premium fuel in a highly tuned engine is based on necessity?

so when Shoot2Thrill says, "The TL uses premium fuel because: Surveys of the public said that people perceive a luxury car to require premium fuel," this may be an incomplete statement, as there are more factors involved

Brettg

There is a lot you can do with ecu programming.
The guys with the VW 1.8T go from 170 hp to 220 or 240 hp
with just an ecu change.
The ecu,s you can buy for it boost the power even more for
premium gas.

A lot of the power increase is added turbo boost, as the cars already
use premium, but if you can advance the ignition timing without detonation,
you can get a lot more power out of an engine.

The TL has an 11 to 1 compression ratio, I doubt the honda engines run it
that high...

Brett

afici0nad0

it sounds like you disagree with the thread originator when Shoot2Thrill says, "The TL uses premium fuel because: Surveys of the public said that people perceive a luxury car to require premium fuel" then?

mojo risin

Pure Adrenaline is right on the money here. I don't understand the whole regular vs. premium debate. America is about choice. You chose to buy the TL so choose either regular or premium fuel to put in it. You know what Acura recommends. If you feel they are wrong then make a choice. It's really a black and white issue. People should not have to be persuaded to take better care of the car they own. That being said, run 87 octane in that TL if you want. I spent over $30k on my TL and I will put 91 octane or above in mine. Good Luck!

angler67

You can refuse all you want, and not all decisions are so shallow, but your statement "your theory is the most ridiculous and absurd thing I've ever heard" is just bit out of synch with the real world and had to be addressed.

If image was not so powerful here in the US there would be no need for Acura, Lexus or Infinity labels as they are really Honda, Toyota and Nissan... using many of the same pieces.

Pure Adrenaline

iTrader: (2)

You're totally missing the point here.

I've already said and agreed that it is the image of the luxury counterpart to have more luxury and more power. This is why I myself opted for my TL-S over the Accord because I wanted the added luxury and the extra power.

However, the argument boils down to the issue of whether premium fuel was required simply for the reason of upkeeping the premium image. It seems that people are under the impression that premium fuel was required for no good reason other than for the fact that Acura is more upscale, therefore the marketing executives decided to require premium fuel simply for that reason. I've provided technical information regarding IC engines, a comparison between a specific Honda and Acura engine, and why our Acura engines actually NEED the premium fuel, compared to the mainstream Honda vehicles which run on regular.

To reiterate, the theory, which I referred to as absurd and ridiculous, stated that premium fuel was required on the Acuras only because they are more upscale. Basically, the theory argued that just because Acuras are more premium than Hondas, it required the more premium fuel. THAT is what I was trying to disprove; not the reason for the existence of premium brands.

Capisce?

SouthernBoy

To jkayca;

The TL could get away with the higher numbers I mentioned IF they increased the width of the tires and made a few suspension changes. But you're right.. it would most definitely be at the limits of a FWD platform.. could be a lot of fun, though.


To crazymjb;

"More displacement = more weight". Actually, if you are using the same basic engine (block and heads), increasing displacement decreases weight if the increased displacement is reached by increasing the bore. But it's quite minimal. For example. An L72 427 1966 Chevy engine weighs less than an L78 396 1966 Chevy engine. These two engines share many of the same components, but the bore diameter of the 396 is 4.09 inches. With the 427, it's 4.25 inches.


To mrbrett;

"Generally when you use higher octane fuel, you will acheive slightly better gas mileage".

If the engine and ECU is designed to operate best with 87 octane, then using, say, 93 octane will result in lower fuel economy, not higher. The reason is due to the fact that less of the higher octane fuel will be burned during the ignition stoke which means slightly more throttle will be needed to negotiate hills, accelerate to speed, etc., etc. A higher compression engine with the peripherals designed for higher octane fuel can better take advantage of this grade of fuel.

When gassing up your car, have you ever notices what other people around you are putting in their gas tanks? I've seen some cars which I know to be designed for regular grade fuel, being fueled with 93, and it's obvious their engine has not been modified. Advertising is a powerful tool and people DO believe the messages.

SouthernBoy

It's kind of a shame this tread's turned to a crap match between some people. I would have thought we were all in here to share ideas, knowledge, and opinions, not to beat each other up about what we thought or wrote.

Common people, treat each other with a bit more respect and listen to what they have to say. A little civility is in order.

afici0nad0

yes...

this is a more plausible explaination for the use of premium fuel.

good debate.

Road Rage

Really some hilarious and childish posts in this thread. All sorts of intircate theories based on nothing but speculation.

I think Pure Adrenaline is on the right track. Most every decision about cars these days is market-driven.

IMO, the TL's engine is rated for premium because it provides the most HP, and that is what all of you look for in this car's price category, right? The difference in power between the TL on 91 octane and the TL on 89 orr 87 octane fuel is countable on the fingers of your hands. This is not blowing smoke - I have eng'g reports from Honda on the NSX, which showed dyno power output for 87, 89, and 91 octane. HP diffs were in the single digits. Torque was slightly more affected, which makes sense given that more spark advance leads to higher cylinder pressures, which changes as RPM rise, to the point where peak power is measured.

The recommendation may also be an attempt to ensure that the best fuels are used - what the industry calls "Top Tier" fuels. Contrary to what many have posted here, all gasoline is not the same, and the fuel additives, both commercial and aftermarket, are further, NOT THE SAME. Some additives (the cheapies - see my post on the ones that are mostly kerosene) can actually leave a coating on the intake valves and injector pintles! And while all grades of fuel get detergent additives, it is not always the case in equal amounts, or not even the same ones. The best add pack always ends up in the premium product, at least initially.

Brand marketing for fuel coincidentally follows the same strategy in this regard as Proctor and Gamble uses for Tide - it always applies its best technology to its premium brand, and then distributes the same technology to lesser brands like Cheer. That "color booster" that they tout in Cheer has been in Tide for months.

"Top Tier" fuels (there are about 8) are very likely to be named by mfrs in a very short time, as warranty claims for all sorts of fuel-related issues increase. High alcohol content from ethanols and other emissions-based fuels often leave gummy residues as they boil off after shut down. And/or they can leave hard deposits on the intake vales and the piston crowns - on zero onterference engines, this can actually lead to piston slapping and bending of the intake valves during the compression stroke!

I doubt the mfrs will insist that the woners use Top Tier fuels, because of all the crap they would take from EPA, consumer groups, Sen. Schirmer types, and the rest - but I think the message will get out.

Some of the TT fuels? Chevron, Texaco, BP Amoco, Shell are good bets. They use advanced additives in reasonably good amounts.

I still recommend a top quality fuel additive, used at oil change time, or in titrated form, for every tankful. I posted on these a long time ago:
Techron
Red Line SI-1 and SI-2
Pennzoil Regane
Fuel Control

I prefer the every tankful, continuous cleaning approach - I use the small Red Line product - that way, dirt, gum, and other crud does not get a chance to gain a foothold. The deposits left by many "clean fuels" highly oxygenated with alcohols are not easy to remove - often, even a strong cleaner does not work, and a really bad case of the crud can require expensive cylinder head work, in the $1k and up range! My advice is to do everything you can to avoid the problem in the first place.