I believe only the 96 models and some 97s were covered... Not too sure, though.

~Cheers~

 

1996 and 1997 TLs are covered as well as most Honda vehicles (but not all)

 

Damn Go90go, that some bad gas mileage. I get like 20 mpg, with Shell 91 octance. 264 is the common number I get all the time and I still have like 5 gallons left in the tank.

 

I'm happy to hit 18, hehe. I was ecstatic when I hit 23MPG!! Pittsburg to San Franciso, drive around the city, then San Francisco to Napa, then back to SF, then back to Pittsburg! Packed schedule FTW!!

~Cheers~

 

I had to drive my 2.5TL to Corpus Christi, TX from Katy, TX and back this weekend. I drove down on premium unleaded and drove around CC and refilled w/ regular 87 (12.4 gal) before returning today. I brought my OBD2 PC monitor and portable IBM Thinkpad and monitored engine functions while driving. Following are my observations:

OBD2 monitor allows Engine Load, Coolant Temp, Air Inlet Temp, RPM, Speed, ignition advance, fuel mileage, mass air flow, throttle position, O2 sensor voltages, etc. to be monitored continuously on a moving graph image. I only monitored one value at at a time although it is possible to set up and do four at one time. Mainly I monitored engine load, ignition advance, and fuel mileage.

1st Leg, Katy - CC, TX w/ Premium Fuel Steady Speeds 65-70 mph, various speed control settings.

Ignition Timing Advance - 33-35 degrees, mostly about 34 degrees.

Fuel MPG - 33-38 mpg.

Engine Load - 50-55% slowly varying as mpg.

Even at apparently very steady speed the mpg slowly varies. It may hold constant for only 3-5 secs, then slowly increase or decrease about the extremes noted. Not sure but think it may be the cruise control gradually making very small throttle movements. They don't show up on throttle position which was dead constant.

When I refilled, the avg. mpg was 25 mpg, well below the peak mpg on the road, but this included a 1/4 tank of around town driving in CC.


2nd Leg, Return CC-Katy, TX w/ 12.4 gal. of 87 unleaded to refill the tank.

No detectable differences in Ignition Timing Advance, MPG, or Engine Load. The same oscillating values and approximate mean values were seen w/ 87 unleaded.

I know others are convinced that premium increases fuel mileage, but my experiment doesn't support this for a 2.5TL. Perhaps a 3.2TL will behave differently. The fuel tank holds 17 gallons of fuel, so there was 5 gallons of premium to mix w/ the 87 unleaded, which may make a difference. I personally don't think pure 87 unleaded would have performed worse or better.

Elevation and wind might make a difference in these results, but elevation change is negligible between Katy and CC, maybe 30 feet lower elevation in CC. Wind is predominattly from SW which would suggest that MPG should have been better on the return leg from CC, but again I could not detect any significant difference. Winds were generally light w/ scattered overcast and light rain on return leg.

Regards

 

 

I'm not doubting your results. But I do question their relevance. Are you suggesting that using lower octane gasoline will not result in a loss of power?

Octane has to do with compression and how well the fuel will resist compression before it spontaneously combusts. This everybody should know.

But the octane needed changes depending on the state of the engine. Under partial load, the pressure in the intake manifold is lower than atmospheric pressure. Only under WOT does the engine get full airflow and compression levels reach their maximum.

An engine idling along or maintaining constant speed is not under heavy load. I suspect that your experiment may yield different results if you tested it in stop and go traffic.

 

Octane rating is only used to affect detonation performance. It does not change energy content of gasoline. Consequently, there is no more "power" in premium than regular. Energy content will definitely affect fuel mileage, but octane rating has no impact on energy content.

Detonation can affect fuel mileage, if the spark knock sensor senses detonation and retards timing to prevent detonation. Lower timing advance results in reduced gas mileage. That's why I monitored ignition advance during the trip.

It could be that premium fuel might perform better than regular in around town driving, but that's not what I tested so I can't say.

regards

 

 

 

Damn straight. I told a bunch a little kids (16-18) that and they had trouble believing me...

Haha...

~Cheers~

 

I see very big difference, between premium and not premium gas in my car, also on high ways.
So, I would advice use premium, it won't hurt it