Got 10% better mileage with premium!

[Ursae_Majoris]

I believe it. In my Isuzu I get 14.2 with 87, 15.3 with 90 octane in the summer. In winter with ethanol in all grades I get 13.3 on 87 and 14.4 on 90. Manual recommends 87. In Taco (which has a high compression engine) I get 16 mpg on 87, 17 on 90.

I started running MMO in both of the vehicles, and average mileage on Isuzu went up to 14.8 (on 87) over a couple of tanks. I add it every other tank, 7 oz to 19.5 gal. 8 oz (my first try) was too much and my mileage dropped.

Do not know how everybody else does it, but I cut bottoms off two Techron bottles and made nice funnels with long necks. Washed and dried 6 24 oz bottles from bottled water and pre-measured MMO in them, 3 for each of the vehicles; 7oz for Axiom, 8 oz for Taco (21.4 gal tank). So at any given time I have at least 1 bottle of MMO in the car, if I forget to refill the other two.

 

[ADFD1]

An OD off MMO will cut MPG's, so will TCW-3. I've fooled around with both MMO and TCW-3, and found it easier to OD with the TCW-3.

Lately I've been making my own funnels too. Cutting off the bottom of the plastic qt bottles of MMO works well too.

AD

 

[Audi Junkie]

I have a clear Gumout vessle I use for 2C oil. Clear means I can measure by eye.

 

[Steve S]

Can happen and does most likley ...the ignition timing increases.

 

[Minou]

My experiment with premium continues;

That previous tankful with mid-grade + indeed returned 7.20L/100 Km over 868 Km.

Last tankful with premium returned 6.93L/100 Km over 842 Km.

So the mid-grade + tankful was approx. right in line between my 4 tankful average of 7.7 and the 2 tankfuls with premium (6.87 and 6.93).

All variables, temperature, traffic, trips, commute, AC use, etc. remained remarkably constant over the period.

 

[Audi Junkie]

fwiw, i put plus 89 in my Accord 2.4 for the 1st time, and the engine really likes it.

 

[Norske]

What do you folks think about filling with premium every second or third tankful? I have a Honda Ridgeline that requires 87 octane (unless towing).

Also, what does tier 1 and tier 2 mean for gasoline? I usually fill up at Marathon...but sometimes go to Kroger (they buy their gasoline from different suppliers, depending on price).

Thanks

 

[mechtech2]

I would not alternate high and low octane fuels, but mixing them may be a good idea, or simply use mid grade.

 

[Ursae_Majoris]

Tier one has more detergents in the gas. If you run T2 (like I often do), your engine will be dirtier. Running MMO in your gas will help to keep it cleaner.
http://www.toptiergas.com/deposit_control.html
http://en.wikipedia.org/wiki/Top_Tier_Detergent_Gasoline

 

[Norske]

Originally Posted By: Ursae_Majoris
Tier one has more detergents in the gas. If you run T2 (like I often do), your engine will be dirtier. Running MMO in your gas will help to keep it cleaner.
http://www.toptiergas.com/deposit_control.html
http://en.wikipedia.org/wiki/Top_Tier_Detergent_Gasoline


Thank You!

 

[Minou]

6.69 L/100 Km (35.2 MPG US or 42.2 MPG Imp.) last fillup yesterday for 2 weeks of driving including a 350 Km road trip. My best score this year. Low fuel light lit at around 900 Km on the odometer. First time I ever do above 900 Km on a tankful in any car. Otherwise most trips 20 - 30 Km with some traffic jams.

Got the ScanGauge II on Monday after ordering it from giffordautomotive.com in Ottawa last Friday PM. Works really well. $187.40 Cdn including shipping and GST.



IGN stands between 33-41 degrees in normal 2000-2500 RPM operation with premium gas. I'll see if those values change when I put regular in it.

 

[Minou]

My first complete (14 days) tankful with the ScanGauge returned:

Scangauge 6.9 L/100 Km vs 6.86 L/100 Km hand calculation or 41.6 vs 41.9 liters actually put in the tank. I entered the small correction and am surprised at the accuracy of the ScanGauge.

I however entered a +2% correction last week for speed and odometer as those 2 values were too low on the gauge vs shown on the car dials.

Still using premium. This last thank returned a bit less than the previous one but did not contain any long highway trip.

 

[chevrofreak]

Your Scangauge was likely showing the correct speed and miles, but your speedometer and odometer were not. You need to use a GPS to calibrate it, not the in-dash speedometer.

On my moms 2002 Subaru Outback, the Scangauge reports the exact correct numbers, but the speedometer and odometer both show higher than it should be.

 

[Minou]

Originally Posted By: chevrofreak
Your Scangauge was likely showing the correct speed and miles, but your speedometer and odometer were not. You need to use a GPS to calibrate it, not the in-dash speedometer.

On my moms 2002 Subaru Outback, the Scangauge reports the exact correct numbers, but the speedometer and odometer both show higher than it should be.


Well, it was the other way around for my car. I had already compared my speedo and odometer with a GPS when I bought the car and my speedo was reading about 2% too high and the odometer 1.3% too low. Now, the ScanGauge showed the speed another 2 Km/hr lower than the GPS and the odometer around 2% too low so I made a +2% correction. I still have the OEM tires with plenty of tread depth left.

 

[novaracer69]

i think that when the did the VE table tunning they did a better job with the high octane table vs the low octane table. there is alot to be hat with ve table accurate tunning based on true afr comming from the exhaust.

 

[Minou]

Filled up with regular on wednesday. Last thank with premium returned a stellar 6.76 L/100 Km for 655 Km and 13 days of driving.

To my surprise, ignition advance is higher with regular gas than it was with premium. Especially when I first start driving with the engine cold and now that it's colder outside. Is regular gas easier to ignite than premium when cold and the ignition can take advantage of it, I don't know?

After more than 120 Km on this fillup, mileage on the ScanGauge looks as good as with premium. Probably got a good batch of regular with no ethanol (Ultramar).

 

[SHOPete]

I think your experience is believable. After reading the same by a Boston Globe auto columnist, I upgraded to V-Power in my 2001 Northstar Aurora and mileage increased ~10% from 22 to 24 or so.