It not synthetic from the factory, if it was the oil company would brag. New dino oils are made to run that long because of cleaner gasolines and lower sulpher levels.

 

Glad to hear that they put dino in at the factory. Now I wonder whether the cars that the factory recommends to run on synthetic, don't actually use dino to help things break-in. At least when it comes to piston rings, I think a little friction is good.

My big test comes with a well broken-in engine, all oil changes just after the "mileage minder" went to 15%. I'll put in the synthetic and measure mileage again but won't do another 3.5K highway trip until next year.

 

[QUOTE=Blueskulker;879769]The "premium" vs "regular" (unleaded) debate has been going on for some time now and on many forums. The bottom line is that "premium" is really a fuel that is Less volatile, and thus less likely to ignite under higher pressures. That is why they use is in high compression engines, such as anything with forced induction. When you increase pressure, you also increase temperature, and with that you can get the fuel to pre-detonate in those type of engines. So you need a fuel that has a higher ignition point. We are talking milliseconds here but it can make a difference when compared to a normally aspirated engine. If used in a low compression engine, "premium" will actually post detonate, and give you a slower burn, with more unburnt fuel left over to be vented out the exhaust, and with that, less power. Not to say what may happen to your pollution control devices if used over time. You get less power, as you are burning you fuel less efficiently, and thus use more as you go through a tank-full as you numbers would indicate. Bottom line the higher the octane the higher the ignition point of the fuel.



Your are right to a point, Premium gas builds more pressure and the end gases run cooler so not to knock. Premium uses less timing except in lean mode.
Premium actually burns faster building more pressure, A car doesn't use all the fuel burnt only 33 percent the rest goes out the tailpipe and cooling. The advantage of premium is it burns faster you dont need to press down on the pedal as far and goes into lean mode faster which means less gas being burnt. A low compression motor usually has lots more timing than a higher compression because the lower octane burns slower. February 2009 Total Performance Solutions .,How, EXACTLY, does the ECU work? - Toyota Tundra Forums : Tundra Solutions Forum ., The new cars adjust fuel trim and timing at every point. If premium didn't burn faster then you would be using regular in a turbo motor.

I guess you all are to young to remember owning a 10.5 compression motor with 89 octane fuel and you drove it down the street and your car would over heat and knock 50 percent of the time. You would have to richen the carb and retard the timing because to cut power so not to knock. Thats what happen when you run regular. Yes Honda motors can run regular but can run premium more efficiently too.

 

Go to the blog https://www.fitfreak.net/forums/2nd-...tml#post881927 Page 5 there is the answer. The owner manual said you can use synthetic but it has to meet API standards and weight. Ive ran synthetic oil for 15 years but now I think I will use dino.

 

This is all great info - should go in its own thread, not buried under a reg/prem fuel discussion.

 

I dont like wasting money either. The first tank was 36 and the second was 35 and I added mid-grade and mileage went up to 37-38 then I put premium gas and averaging 40+ mpg on the car. The best I got was 47 and the worst I got was 38 with premium.

 

Thanks to K_C, I invite eberyone interested in the great synthetic vs. conventional (dino) motor oil debate to go to https://www.fitfreak.net/forums/gene...-dino-oil.html

Maybe we can further improve our mileage and engine life at the same time.

 

I just want to add that there is an food grade Polymer additive Viscon - Manufactured By Viscon California (just to explain the additive) It helps the combustion of the gas and every brand has their own formula. If you notice Shell,BP and now Mobil as of July 1 of this year has an additive that coats the engine so carbon wont stick and makes the engine more efficient. Premium has more than Regular, also that additive goes into the oil to help the oil work better.

 

Are you talking about the additive package? Chevron advertises Techron. If so and the additive package is three times as much in premium as regular (per Chevron advertisements), there may be long lasting benefits of using premium that we have not previously discussed.

 

It works with it. PIB was is an additive made to keep jet fuel from exploding, They use it in diesel and gasoline with ethanol so there is no phase separation.

 

Ive used it for 15 years, I had Chevy Malibu v6 that got 35 mpg plus with it. You are getting very good mpg so use what you want, not every car needs it now but when the time comes you will know. It takes a few tanks so the car can adjust to it.

 

I've found that following the owners manual is a lot less hassle than collecting data !! I thiink the manufacturer is wiser concerning these matters than I am.

 

The Audi and the Fit both have extended oil change intervals, and I find it hard to believe that they came with dino juice originally.
All us old schoolers liked to first change oil after 1k, to rid the engine of casting sand and metal shavings, (IIRC, Jeep advised you NOT to change the oil before 1K) but that now seems to be a non issue. I'm guessing break-in on dino juice has also gone by the boards.
With the fixation on gas mileage numbers, if a mfg can boost his numbers a bit by going to synthetic, I'm sure they do.
Conversely, any vehicle I've changed over to synthetic from dino has shown no improvement whatsoever. That includes a Jeep Cherokee, a Passat, and the current Jeep. (full disclosure-I haven't done any statistical analysis, either; just eyeballed the numbers)
Using an onboard computer takes one variable out of determining your gas mileage, but the type of trip and any variations in your driving style will factor in as well. It is really tough for individuals to come up with carved in stone, definitive mileage numbers. This, of course, is why the EPA's test cycle numbers are used.
Moon

 

What about breaking the engine in and making the piston rings seat? You need a bit of friction and heat to do this. Since synthetics reduce friction and don't breakdown under heat like dino, would it make sense to use synthetic from day 1?

By the way, did you see my mpg numbers for driving I-5 North and South from LA to Seattle and back. I tried to make it as real life as I could without using a dyno and special fuel measurement readings?

 

Oil has come along way and still changing. Group 2+ oils can go 5000-10000 miles easy and group3,3+oils is dino oil now considered synthetic that goes to 15000 miles and trying to go up to 25000miles. The main reason that oil was changed, is that gasoline had 150 ppm sulpher and now has 15- 50 ppm so less acid in oil and can easily go to 10000. If you drive server driving then 5000 miles is when you should change. Ive use synthetics for 15 years but is it worth the cost, Oil thickens up so cleaner oil means better gas mileage. I cant believe I just said that. The oil is clear that they put in, 5w20 synthetic has a yellow tint. So I am positive that its not synthetic from the factory. You should always monitor your oil and if in doubt change it.

 

If in doubt, change it out..... Sounds like a winner to me.... I always have oil and filter ready for those doubtful times.... Gotta change the oil on the old pickup that is seldom driven and still has 7000 miles to go according to Mobile1....

 

I've experimenting with octanes myself, and during the summer months I'm seeing no change at all in mileage between 87 octane Shell or 93 octane V-power. I usually put a tank of 93 through my car each month, just for the added detergents in the V-power. With such low compression, it would make sense just to use minimum required.

I work for Audi and we've had huge issues lately with direct injection engines and crappy fuel below the 91/93 octane threshold. Basically the only fuel the big german 3 stand by is Shell V-power, or BP 93/91 as they are the only 'Tier 1' fuel suppliers on the east coast.

To halfmoonclip, the Audis will run on 87, but they naturally retard timing and pull back boost to limit knock. On 93 versus 87 you can actually tell the difference in fuel economy and performance. We had a slew of customers with older 3.2L A6's and A4s who asked what we had done to their vehicles to make them go faster after we had done induction cleans and then filled their tanks with 93 octane shell.

 

I'm totally confused by V-Power not being available in my region. It is an excellent fuel and, yes, cycle hytest through twice a year for a month.

The additives are available OTC and I would prefer to add a bit every fifth tank, but not running numbers....

But how come no Shell? What is their distibution in the North East? And how come I'm not hearing a lot about 'Tier 1'?

 

I like Shell vpower usually produces more hp over other premiums,but Bp gives me more mpg. Vpower has a minimum of 8 percent ethanol and Bp doesn't use that much (5percent) ethanol in there premium if any. Thats why they are not considered top tier gas.

 

Thanks, GW Fit , for the best data I have seen, and a pretty good argument that with a stock Fit, the difference in gas mileage between regular and premium are probably not statistically significant.

If I read right, you used both grades in each direction. Is it reasonable to assume that when you changed from one to the other, you ran until the tank was almost empty? 1500 miles in each direction is only about 4 tanks, so that sounds like 2 tanks of each.

Re the onboard mileage meter, over 5000 miles (since having the software upgrade), reported gas mileage has been, on average, within 0.2 mpg of calculated mpg. Differences have been as large as +-3 mpg, but I suspect that reflects operator error due to the difficulty of getting a consistent fill on a Fit (unless you are way more patient than I am). This is confirmed by the variation being greatest on fills when the tank is more than 3/4 full, vs nearly empty.

My final observation is that gas mileage seems to have improved after passing 10,000 miles.