What about these gas treatment things, any good?

 

Good for nothing that Top Tier gas won't do.

DryGas to combine with water: Unless your tank has been sitting almost empty across several seasons and collecting condensation, pump gas has enough drying agents.
Octane Boosters: Ever since tetraethyl lead became illegall, lead subsitiute chemicals to retard combustion are used. They tend to make deposits on valves and combustion chambers.
Fuel system cleaners: Top Tier pump gas has detergent additives to keep injectors, valves and combustion chambers clean. Fuel system cleaners were originally designed to clean gum from carburetors as you drive. I don't know that they will remove gum from a modern system. I do know that a friend who did not use Top Tier gas had sticking valves and very poor mpg, and the Honda dealer ran some of this through her system and charged a couple hundred $$:

BG Induction System Cleaner, 3Part MI 3000plus $88.95
“BG Induction System Cleaner, 3Part MI 3000plusBG ISC Induction System Cleaner will quickly and safely clean fuel injectors and remove hard, baked-on carbon deposits from intake ports, intake valves, combustion chambers and EGR ports. For complete clean-up, BG ISC should be used in conjunction with BG MI 3000 + added to the vehicle fuel tank at time of service. BG ISC will not harm gaskets, seals, hoses or any component in the fuel system. Professional Grade Feeder System Included & required.
http://carfood.com/megpowentuni.html

So evidently that cleaner is thought to work.

 

BTW, it is not poured into the tank. It is a shop procedure, supplied direclty to the fuel injection system under the hood.

 

When my friend told me the Honda dealer was using a chemical solvent to remove the crud left left on her Element's valves by non-TopTier gas, I said "snake oil" and doubted it would work.

Sure enough, today she says she only got a few hundred miles before the Check Engine iight came on again, indicating a valve or valves were not closing tightly and making the engine run inefficiently.

The cylinder head will need to be removed to clean or replace the valves. Surely the cost will be more than the savings of using low-detergent non-TopTier gas.

 

That looks to be very old and out of date. I bet its lowered by 12+ not 5 to 7.

 

Very old. I would lower it by 20.

 

My xB runs just fine on the lowest octane I can find. I don't understand what this controversy is about.

 

87 oct. Shell with the 5% discount and be done with it.

 

It really is amazing how many times the same things are discussed. If all the discussions of octane/milage/power were in only ONE topic, all the information would be easy to correlate. With the same stuff being talked about over and over in separate topics, folks are not exposed to all the information that went before, and don't learn from it.

Anyone REALLY interested might want to take a squint at some of the other topics about this.

Maybe one can start here: https://www.scionlife.com/forums/viewtopic.php?t=116693

 

It's also amazing how much bad info is being slung around. I really like the one about the more octain the better. That made me laugh.

 

Do you believe that 10.5:1 compression ratio can run on 87 octane without any intervention in the ignition timing by the ECU?
Do the rate and amount of ignition advance have anything to do with power?
Have you heard how a car with 10.5:1 but without ECU runs on 87 octane?
The xB runs perfectly on 87 because of its ECU.

 

Question:
If you were going to tow a trailer in summer heat on the Interstate, which octane would you recommend to this thread?
https://www.scionlife.com/forums/vie...434&highlight=

The correct answer is:
a. The xB is designed to run on 87 octane.
b. The xB is not designed for towing.
c. All of the above.

Guess those answer the question ;-)
But they won't stop someone from towing.
So what octane would you tow with?

 

Tiny correction from owners manual:



87 octane or higher. :D

Tomas

 

That is on page 124.
Is the manual saying that if you can't find 87, higher will still be OK?
Or is it saying that 87 is the minimum, and higher is better?

The first answer goes without saying.
In view of the xB's high 10.5:1 compression ratio, the second answer is likely the point of the "higher".

The manual goes on to say three things:
1. Lower than 87 will cause persistent heavy knocking.
2. On 87, if you detect heavy knocking, or if you hear steady knocking on level roads, see the dealer.
3. On 87, light knocking for a short time while accelerating or going up hills is normal.

Question...
Why would knocking for a short time be normal? Because that is the time it takes for the ECU to intervene and retard the ignition (detune the engine). That reduces power.

Another question...
If you wanted to avoid the possiblity of knocking and having your power reduced while accelerating, going up a hill, or towing a trailer, what action would you take:
a. Ease off the accelerator?
b. Switch to a higher octane?

Me, I like the second choice. On 91 to 93, the engine pulls hills at 2000 rpm without a knock, accelerates like its modded, and gets 37 to 42 mpg on trips.

If I was willing to spend the time and money to mod an engine, I would not overlook high octane as the easiest and cheapest assist for a heavy foot.

 

Exactly the point I was making in the post I linked to about six or seven post up from here. :D

https://www.scionlife.com/forums/viewtopic.php?t=116693

 

vintage42, you can run whatever octain you like. It shouldn't hurt anything except your wallet. I've tried 93 and just didn't notice any difference in power or mileage. So to me, why would I pay more for the same of everything.

 

Well, if higher is better, why doesn't the manual come right out and say that?

It could, but there is no need to, because the xB performs well on 87, as many here will attest. The car has a high enough power-to-weight ratio, and good enough engine management, to have good performance on regular. High octane is unnecessary. And it would not be good for Scion to give the impression that such an economy car can benefit from expensive high octane.

However, Lincoln was in a different position with the 2001 Continental that we almost bought last Summer. My wife loved the looks, handling and power. But the Owners Manual said to use Premium gas, though Regular could be used but would result in lower performance. The Continental evidently needed all the power its high-compression V8 could make, in order to give the performance expected of such a car, and Lincoln figured the owners would not mind paying for it. But my wife hates expensive gas, and I told her Premium would be $3 in a year (so now it's $3.20 here). She bought a low-compression Buick that uses regular and cannot benefit from premium.

 

There is no need for most people to use high octane. People who accelerate hard all the time, drive in hilly country, and pull trailers may want to try it. Unless the tank is nearly empty of regular gas when filled with high octane gas, it will take a couple of fillings to achieve high octane in the tank.

 

It would be hard to notice. You would have to run the 87 completely empty so the next tank is all 93. Then you would have to drive the majority of the time such that the ECU would be intervening on 87 but is not on 93. Like continuous heavy throttle in mountains or at high Interstate speeds. High octane might gain a couple of mpg under those conditions.

Most people are going to change to 93 by filling up with 8 gallons, then driving normally, and saying wtf. If they persist with 1-2 more 93 fillups, they will achieve 93 in the tank, but hundreds of miles and many days may have passed, and it's hard to remember what 87 was like.

I am sure my 37-42 mpg highway figures are almost entirely the result of pedal management.

 

Assuming that, like most people, you find no benefit from high octane, there is a reason wny you still might want to use it.

The list of Top Tier gas retailers is limited to 14 because:
"Gasoline retailers must meet the high TOP TIER standards with all grades of gasoline to be approved by the automakers as providing TOP TIER Detergent Gasoline."
http://www.toptiergas.com/retailers.html

More retailers would qualify as Top Tier if their 87 had the same detergents as their 91-93. If you can't find a Top Tier station to buy your 87, most everybody's 91-93 would qualify as Top Tier.