hypervish

Hey all,

I've noticed that the few times that I've tried to hypermile, that the MPG isn't as good as driving hard. LOL, yes, I'm serious.

From what I've seen, and it's not scientific at all so don't take my word for it.

IF you get up to speed slowly, like 1.5k rpm and leisurely get up to speed then the mpg isn't that good.

IF you get up to speed quickly, like 3k rpm, maybe more the mpg is good since once you get up to speed you can get off the throttle and only apply light throttle to maintain speed.

I've been able to get 19.8 mpg in the city, by accelerating hard and coasting a lot. If I get up to speed slowly, I end up around 17.8 mpg.

And, If I just accelerate hard, without coasting and keep my foot on the accelerator I end up at 16.7 mpg.

Help me make sense of this. BTW, these numbers are hand calculated.

My question, has any one seen this occur on their RX? i.e. drive hard = better mpg

On other cars', you usually get the best mpg by driving gently. However, that doesn't seem to be the case here.

I do know that the RX will upshift immediately upon letting go of the throttle, so I suspect getting up to speed quickly and then coasting allows it to get into top gear quicker than getting up to speed slowly.

Also, what is your sweetspot on the highway for the RX? I've seen in the past I think, people saying it was 70/75? Is this accurate?

I plan to find out my sweetspot and report back, but I thought it would be nice to have a few datapoints.

I understand the best mpg is going to be with 4th gear and TC locked. Which I think is around 40-45 mph on the RX300.

In case you didn't want to read the entire post, I've put my questions in bold.

Thanks!

salimshah

Fast acceleration and coast giving you better mpg is not a unique thing to RX.

There are lots of things that influence it ..
Your gearing ratio.
Programming of auto-trans ... (shift points)
Computer learning and adapting to your driving habits,
drag and all other source of loss of energy
inertia
coasting vs braking

Good luck in your quest.

Salim

CharBaby

My sweet spot on the hiwy is at ~60 mph/<3000 rpm and I can actually get between 23-24 mpg. Any faster has always gotten us <22 mpg(worst) and I've been checking for 12 yrs.

80 mph and we're <20 mpg. This is all with Cruise Control. Anytime I get on the accelerator pedal at all, our mpg just drops. Regardless of the Octane that I use though, 93 does get me slightly better MPG.

We can get 19-20 mpg in the city mode when driving very easy or cruising slowly in the urban areas. Slow acceleration from stop signs/signal lights and baby the throttle like walking on egg shells.

I have had "fun" with the RX(accelerating hard and cruising hard/stomping on the gas, down shifting manually etc.) and , I'll get like 15 mph.

I always read my mpg with a calculator after filling up with gas and check it with the display on the Blue Screen(which I clear after each fillup). The screen is(almost always) 1 mpg better than the calculator, especially if I give the gas pump a few extra clicks. If I stop the gas pump when it clickz off by itself, the readings are closer/even(within a 1 or 2/10ths).

What is your final drive ratio. I know that in my year('01-'03) it is 3.08:1(FWD) & 3.29:1(AWD). This may have been new for 2001(different than '99-'00 ???), IDK! There were lots of new upgrades in '01 as we talked about in a previous thread.

It's hard to say really!

salimshah

When studying speedo dial, I was intrigued as to why the max speed shown was never the max speed the vehicle would attain (unless dropped from a plane). I was told that it is marked as such as the OPTIMUM speed is supposed to be number at the apex of the gauge.

But that was before digital gauges and some weird displays.


Salim

MrCelloBoy

Hybrids work this way. By smoothly accelerating to the desired speed you spend more time cruising at reduced RPM's once you're there.
We avg. around 19mpg in our 2010 450h; regardless of fuel type, in mixed city and fwy. driving.

hypervish

That's interesting! Good to know.

99rx

iTrader: (6)

How funny that you bring this up... I've been having to drive to work, that is now 60 miles from my house round trip, after my company moved. I decide to drive my 2002 Honda Accord 2.3l 4cyl 128,xxx miles for gas purposes. This past week or so, I've been testing the theory of gently getting up to speed, not going over 3k rpms AT ALL. I'm doing this to see just how high can I can the mileage. Shifts nice this way, but 4-5 days in, I see my mileage at a certain point on the gas gauge is substantially lower than when I accelerate at about 3-3500k rpms to get up to speed quicker. Testing the theory of accelerating slowly has gotten me an average of roughly 23-24mpg with 90% of my drive highway. When I drive normally (3000-3750rpms) I average about 27-28mpg. Same drive. Granted at this mileage, it could use new O2 sensors for good measures and gas mileage improvements (no codes). I refuse to drive the RX on my treturous drive to work (construction, sand, rocks, etc). And for the fact that it doesn't get the best mileage. So for now it remains the weekend around town car.
So that's my story for now. If I end up driving the RX for a week, ill report on that, but don't count on it.

hypervish

Keep us updated, if you do!

Boltzmann

I have no problem whatsoever getting 24+ mpg on the highway even though my RX is 14 years old now. I'm not sure what I'm doing differently. I don't hyper-mile, I drive uphill as well as downhill.

kalali

A non-hybrid RX gets better gas mileage than that. I suppose the hybrid advantage is in city driving otherwise its totally pointless.

CharBaby

My worst hiwy mpg in our RX is when traveling from Western NY State down into Central PA(State College). Bearly 20 mpg.

Our best mpg in our RX is when(driving conservatively/easy w/CC) traveling mostly through Western NY State(I-90) without all of the mountainous highway travel and mostly flat road where we can achieve over the EPA estimate for hiwy(22MPG) and have obtained 24 MPG but, it's not often the we can get much over 22 mpg anyway. Our city MPG differs between me and my wife(mine is always better)

I have done the "relearn" thing(whether disconnecting the battery or ECU-B/EFI Fuses) and have tried a more aggressive driving style for several tanks of gas but, only got ~17mpg city regardless of octane compared to 19-20 mpg while driving conservatively as mentioned earlier.

hypervish

I've only once gotten 27 mpg going about 45 - 50 mph following an RV.

Aside from that very rare occasion, unlikely to ever happen again I've gotten 25.2 mpg out of an entire tank going 70mph.

I've been able to duplicate a few tanks of going 75-80 mph and averaging 24.8 mpg.

But lately I've been running the RX hard and end up at around 21 mpg highway. Need to slow down! But it run's so well on the highway.

I've noticed the biggest improvements in mpg after cleaning the MAF.

2KHarrier

You guys are going to laugh at me, but I recently took a long road trip in my RX and just for fun, I tucked the side view mirrors in on both sides of the doors and I actually picked up about 1.5 mpg while cruising. I stayed in the right lane, and doing my standard 65 mph, I ended up averaging 25.1 for the 2 hours I kept the mirrors tucked in. Once I started getting back into city traffic, I figured I better extend them out again.

Thought that was a rather interesting result...

hypervish

Not exactly ideal, but nonetheless interesting results! LOL, I don't think the cops would be too thrilled about driving without using the side view mirrors.

Although this get's me thinking, I wonder how big of an impact removing the roof rack will make on mpg on this particular car.

I've seen the effects on a different car via this link: http://metrompg.com/posts/roof-racks.htm

It'd be interesting to see if the impact on mpg is the same with the RX as it was with the Metro.

I think I may remove the crossbars and see the effect. I don't think I will like the way the RX looks without them though, which is why I've kept them on all this time.

Boltzmann

I'm curious, too. I hardly ever use my roof racks, so it wouldn't pain me to remove them if it results in better gas mileage. The only reason I leave them on top of my car is for aesthetic purposes.

Oh, and I'm a little on the lazy side ...