iamhomin

Okay, here's the thing.

My TSX is still a baby, only 280 miles on it. It's still in the break-in period so I have yet to drive it aggresively, however it already drained 17 gallons of gas. WTF? That's like, 16.5 miles per gallon and I drove mainly on the highway.

Before purchasing my TSX(6mt), I drove a 2002 TL(at) and going from a v6TL(2002) to a i4TSX does have it's disadvantages. When my TL was on the highway, the rpm was usually at 1.4 @60mph, but for the tsx it skys high to 2.9~3.1 @60mph. God, I remember someone posting about how they got 38 miles per gallon, but how's that freaking possible?

1st -> 2nd, shift @ 3k rpm (usually at around 10mph)
2nd -> 3rd, @ 2.8k rpm (~21mph)
3rd -> 4th, @ 3.1k rpm (~33mph)
4th ->5th, @ 3.5k rpm (~49h)
5th -> 6th, @ 3.5k rpm (~49 mph)

What do you guys shift at???

Lung Fu Mo Shi

Did it REALLY drain 17 gallons, or did the light just come on. It only has a 17.1 gallon tank...and fill ups are usually around 14 gallons.

Crazytree

http://www.acura-tsx.com/forums/show...&threadid=2829

inkytawney

See the other discussion on economy. entitled 19 mpg...
anyhow, I have a six speed tsx. I have never ever gotten less than 30.5 mpg. My last was 34 mpg. 75% of my drive is steady level expressway at 65-70 mpg. Strangely the TSX gets worse gas mileage on my turnpike (80 MPH). due to performance gearing of the 6 speed. I redline the car at every on ramp but run in highest gear otherwise in normal driving. If you live in 100 % city driving in lower gears then that may be it.
My old 00 TL got 33 mpg on the highway.

iamhomin

The light indication went on when I was at the high 250 mark. It's crazy.

iamhomin

65-70mph? What does the tachometer read when you're at those speed?

rb1

Actually, this really isn't strange at all. The force required to overcome air resistance increases as the square of your vehicle speed. For example, the drag force on your car at 60 mph is almost 10 times what it is at 20 mph.

So fuel economy tends to fall off rather dramatically as you go faster. You can in generally get 15-20% better fuel economy going 55 than you can going 70, etc. There are some benefits to having taller gearing (engines are generally somewhat more efficient at lower RPM/higher throttle than higher RPM/lower throttle), but fuel consumption certainly won't go down linearly with your overall final drive ratio.

jcg878

That light is way too conservative - you've got a lot of gas left when it goes on. Use the gallons put into the tank to calculate mpg, not 17 gallons. If it went on after 14 gallons, you're getting 20 mpg (280/14). Still sucks, but it's what I am averaging (20mpg) after 4500 miles.... albeit in 100% city driving. I get up to 26-28 on mostly highways.

inkytawney

TACH at 70 is right at 3000 rpms.
TACH at 65 is right at 2750 rpms.
This must be a sweet spot since my mileage over 2300 miles stands at 32 mpg.
SHIFTING. Depends on situation.
But I get to highest gear possible.
I still love to redline getting on expressway.

jcg878

Man do I feel dumb for never thinking of that as the explanation for why fuel economy drops dramatically above 55. Air resistance increasing exponentially makes so much perfect sense. I always thought "sure you use more gas, but you're going faster, right?" Obviously it isn't linear.

Wing

Man are cars getting worse and worse on fuel? Certainly seems like this push for power we have (horsepower wars) are really starting to get us into trouble again with fuel.


I just returned my RX8 9mpg is not for me! I usually averaged 18-20mpg, no freakin' way was it possible to get more even on the highway!

So I'm looking at the TSX but it's not the greatest either, and the TL doesn't look so good.

Interestingly the 350z seems not bad, I've read of 32mpg highway!

majormojo

Yeah, the RX8 fuel economy is disappointing. I had an RX-7 and it was pretty bad too. OTOH, I'm amazed that the Mazda engineers can get a rotary engine to meet modern emissions standards at all. In general, the rotary strikes me as a cool idea whose time has passed.

To stay on topic, I haven't bothered to calc the actual fuel economy on the TSX yet, but the feeling so far is that it's not great, but not bad either. Worse than my 2.0L Accord, better than my 5.7L Suburban.

peetah

Caution about 350z mileage: Nissan/Infiniti typically overstates gas mileage. Check any G35 forum, and you see lots of complaints about actual gas mileage. I have two friends with G35: one with sedan getting 20-22MPG mostly highway driving, and one with coupe getting about 15MPG!!! But he's still breaking in the coupe, though he is driving like a granny (not revving above 3K). 350z and G35 uses basically the same engine, so don't expect 32mpg.

I got 29mpg on my first tank on my TSX, so I'm pretty happy. I believe Honda/Acura's EPA gas mileage numbers are pretty acurate.

rb1

Maybe this is a new thing. My 99 Maxima averaged 24.5 mpg and routinely did 30 mpg on the highway. Seemed pretty much in agreement with the 22 mpg city, 28 hwy mpg rating...

Wing

The 32 I quoted was from a owner... that might or might not be blowing smoke.

Actually Acura seems to be overstating fuel economy. The TL brochure states 7.2L/100Km highway the Tranport Canada numbers on the sticker was 8.3 or something similar. So higher!

gogozy

with the weight of the car, i am pretty impress about the fuel efficiency. fuel consumption for i4 or v6 on highway is not much, but i think it make about 10-15% differences on local/city and idel time. with it's power and weight, i am happy with it's efficiency. i generally got 11-12km/L on 40city/60 highway driving, but i know winter time it will lost about 10%....

kwongster

I have about 1200 miles on my TSX (5A, non-navi). This is my first post, so apologies if I screw something up.

My MPG started at 24.5 mpg but it gets better with every fill-up. I do probably a 60/40 street/highway mix and a recent fill-up hit 27 mpg. I took it on a "road trip" -- about 250 miles on a highway/mountain pass -- last weekend and it hit 31 mpg. And when I had to pass a car on the two-lane highway, it moved like the other car was standing still.

I had a 5spd manual 1994 Integra that got 30 mpg on a regular basis (regular fuel, sigh), and I hoped the TSX would get about 27-29 (knowing I was giving up some MPG for other perks off the TSX); I even opted for the automatic instead of the manual because its MPG numbers were slightly better. The TSX seems like it's going to be in the ballpark for MPG.

I do miss the manual, though!

peetah

It is unusual for the automatic to have better gas mileage than the manual. With 6 speeds instead of 5, you should think the manual should be able to offer better performance AND gas mileage. But for some reason, the 5th gear on the auto is actually taller than 6th on the manual.

But for added fun, the 6 speed is definitely worth the 2 MPG.

Bear Trap

Acura felt, and rightfully so, that manual drivers would buy the car for a sporting bias and gave us closer gear spacing to better keep us in the rev band. This also assumed fuel efficiency would be a slightly lower priority (again right on target). My only question is then where is the 7-speed? I don't have to shift from 6th to pass if I'm doing over 60 mph, so a highway gear to drop the revs to 2500 at 70 mph would be nice for 35 mpg!!! I want it all!!!

ClutchPerformer

It sure would.....

kwongster

Excuse my ignorance, but what does that mean, that the 5th gear is "taller"? What does that do to a car?

rb1

"Taller" just means (somewhat backwards) a smaller gear ratio and hence lower engine RPM at a given speed.

All they mean here is that, for a given speed, the AT car's engine turns fewer RPM than the MT (in top gear, 5th on the AT and 6th on the MT)

rb1

It is frequently true that top gear in today's 5-speed AT cars will be taller than the final gear in the MT for the same model (and actually true in many 4-speed AT's, too). MT's usually manage to eek out better mileage nonetheless because frictional losses are less (even with the torque converter lockup in the AT).

Easing up on that lead foot will help fuel economy a lot more than a 5-10% change in the gearing. I bet a TSX would top 35 mpg on the highway if driven at 65 mph or so. Also, remember that *every* time you use your brake, you're wasting gas. (Of course you have to use your brakes, but there are lot's of opportunities for anticipating stops and coasting more and braking less)

If they make the TSX gearing any taller it will make me less likely to get one, not more. But of course everyone is entitled to their own opinion.

peetah

I totally agree!! It may sound a little crazy, but not long ago, autos only had 3 speeds vs 5 today. Why not 7 for manual and make everyone happy !! I bet we'll see this in a couple of years.

ClutchPerformer

Same here. Don't get me wrong, I love the close-ratio gears, but I still maintain that even with a close-ratio box, 6th does not need to be close to 5th. When will you ever shift 5-6 at redline? Probably never.