PsychDoc

...Just thought I'd give all you guys and gals a little update on what this incredible engine/transmission combo is capable of.

I gassed up and immediately got on the highway and drove straight for about 45 miles at a fairly steady 65-70mph with the climate control shut down (it was 68°). When I got off the highway and rolled up to the first light the "tank ave." told me I had done 34.2mpg !!!

About a mile later after a bit of stop and go traffic it was still reading 33.3!

The way I figure it, this incredibly efficient power plant, with its VERY healthy 272hp on tap is giving me over 50% better gas mileage than I was getting from my '02 ES 300 (good for only about 23/16mpg in real life driving).

I'm a bit surprised that the almost incomprehensible efficiancy of this engine doesn't get more press. It's really unbelievable. And, let me tell you, when you need the power and you put your foot into the accelerator, this thing is a rocket ship!

Heck, the way I figure it I'm still "only" paying the equivalent of about $2.25/gallon.

Nextourer

whoa! That's ~ what we get in our 02 Camry XLE on the highway ... and it's a 4 cylinder!

amf1932

Ideally the best way to get an accurate gas mileage check is to go to a gas station and fill up at the same pump for your tests. Since it's not a good idea to top off your tank, I would fill it until the pump nozzle clicks off, then put on your gas cap and set your trip mileage to zero. I would then drive the car for about a half a tank, then pull up to the same pump and once again fill it until the pump nozzle clicks off. You then check how many miles you've driven using the odometer, then divide it by the number of gallons used.
Doing it this way will give you a very accurate gas mileage check.

Using the trip computer to check your gas mileage is not accurate.....it just gives you a rough idea.

PsychDoc

***Using the trip computer to check your gas mileage is not accurate.....it just gives you a rough idea. ***

I'm afraid I have to disagree with you here. I've found the trip computer on the ES (both '02 and '07) to be almost deadly accurate to within 0.5mpg over and over again.

Ideally, of course, you are correct and what you suggest will give you an accurate read down to the 1/100th of a mpg, but in real world applications, who cares?

±0.5mpg accuracy is plenty good enough for me!

amf1932

Congratulations........you are the first Lexus owner that has such an accurate trip computer!

I've been a Lexus owner since 1990 and I NEVER had such accurate readings.

A 1990 ES250, 1994 ES300, 2003 ES300, and this 2007 ES350.

jeffofla

And I am not sure that they are accurate on mine 2007 ES 350 either. For example, when I put the car on cruise control and then hit "avg speed", it is usually off by about 3-4 miles per hour aganst the speedometer. So which is right?

wizhill

I think it calculates the average speed from first movement. The other day my wife and I were running errands and I left her in the car (with it running) while I ran inside a store. When I came back out I checked the average speed, and it had shot way down...

On the other hand, when I drove straight down the I-5 freeway from Northern Cal back to Southern Cal for hours, the average speed was really pretty close to the cruising speed.

Macklin

That's great highway mileage. I only got 32.2 when I did the same thing; although, I was running the AC.

My mileage computer has been consistently optimistic by about 1 mpg over my calcs. However, as I've said before, I'm thrilled that I'm getting about the same mpg as my '98 ES300.

jeffofla

Fine. So if I have set my cruise control and I then reset the average speed, shouldn't that first movement and the cruise control speed match?

twister

All this MPG talk made me ask this question again. So, which gas are you using? I d/l pdf manual for ES350 and it talks about premium high octane gas. Will it be possible to use a regular gas? Or, do you think it will cause permanent engine damage? Will it affect gas mileage? At my dealership they told me a rep from Japan confirmed it was OK for a regular gas. But, I'm not sure if this *info* was a part of a sales pitch to make me forget about premium gas prices

I'm just thinking that theorically its the same V6 engine as '07 Camry, so why not use a regular gas?

... still waiting for my ES350 to arrive - one more week to go....

PsychDoc

Ah, the eternal "regular vs. premium" question. This is becoming somewhat akin to the "chicken or egg" question, isn't it? Having read through all (or at least most) of the posts on this subject I think it's fair to say that there is no real consensus.

Some will say using 87 will cause the engine to "ping" while others say this is poppycock.

Some say using 87 will cause lower gas mileage, others say that's just silly.

Some say the engine will run fine but will be permanently damaged in some mysterious, as yet, poorly understood manner. Others say, "now we're just getting carried away."

Blah, blah, blah, ad nauseum.

Simple fact is it's probably perfectly fine but because I'm a big wimp I'll stick to using 91+ for at least a while. FWIW my '02 ES 300 also "required" premium and I used it for the first 3 years. Then (for reasons I can't honestly recall) I switched to 87 and didn't notice one damned difference.

Don't expect to get a definitive answer on this, I don't think one exists. The only way this could be resolved once and for all is if the great god "Corporate Lexus" came out with a divine decree on the matter. Sadly, for reasons that escape me, they don't seem to be in any rush to resolve this issue.

tnfan

Twister, here is the link to the previous thread on this. Looks to be no defnitive answer on this. BTW, I am using premium in my car and have no plans to switch.

https://www.clublexus.com/forums/sho...d.php?t=216377

amf1932

This is taken from the ES350 Owners Manual.

Swobro

My company provides me with free 87 octane gas and I re-fuel at the work place. I was concerned about the pinging potential and have been using an octane booster called "104." So far no pinging.

However, one time I filled up without using the octane booster and the (inaccurate?) trip computer indicated that I was ~1.5mpg worse on fuel efficiency (low 24's vs high 25's mpg). I did not experience any pinging for that tank.

I fill up every 3 - 4 days with about 3 gallons left in the tank.

My driving patterns are very consistent, and I log 80 - 100 miles per day.

Bottom line....87 octane has thus far been OK.

Ingram4868

I was told by some people that race in SCCA, that continued use of octane boosters such as 104 causes a buildup on the o2 sensors eventually leading to inaccurate readings.