Toyota Speaks on Gas!

My old service guy was great but then moved to Scottsdale, AZ to work for Lexus! OK I will try a couple of tanks of premium, it will be like paying for gas a couple of weeks ago......

 

I tried all grades as well but 87 is fine for me no issues with using that grade. It's to eaches own really.

 

Any diff between 87 to 89, or d0 you have to run 91+

 

Here it is:

http://www.tacomaworld.com/forum/pe...0-87-vs-89-vs-91-octain-fuel-my-findings.html

 

I did some research before I bought my truck. Some info on the internet said the 6cyl Tacoma used premium, med and regular. Needless to say I was very confused. I called 4 different dealership and everyone I talked to said regular gas (87). My salesman explained it to me like this. The VVTi engine can adjust the engine timing on the fly. Therefore it can adjust on the fly to different grades of gas. The Tacoma can use all 3 different grades of fuel. Not sure this is true or not but it's what I was told. Ive always used 87 and had no problem. No knocking or pinging! I average 375 to 400 miles per tank of gas (highway miles).

 

with 10:1 compression, you should be using 91 imo. I have been filling up with regular because I didnt even realize it was so high. we have 87, 89, and 93 here. I will try 93 and see what happens. I haven't noticed any pinging with 87. I hate using 89 because I have a feeling it sits in the tank the longest.

 

Ran 87 from taking it home up until around 6k. Been using 91 on the last 3 tanks to see if I get the same results as Chris. I might have noticed a bit more smoothness in shifts, or it could be placebo.

Around '05 when autos.msn.com used to have more information, they said Tacos only did premium. However, book says regular 87 is fine.

Destroys gas mileage and costs you more, so far

 

These engines are controlled by a "learning computer". As I understand it, not only does the computer learn your driving style and set shift points accordingly, but it also learns what fuel you use and adjusts spark advance to the maximum allowed without knocking. It has a knock sensor for this. So the only thing that should change would be actual horsepower, and to a lesser degree fuel economy. I have also been told that it takes a couple of tanks of fuel for the computer to readjust so you won't see immediate results. The manual says for maximum power use premium. My truck is plenty strong with regular and it WILL NOT hurt your engine, so my wallet says regular.

 

For some reason 91 octane runs smoother and I do get better mileage compared to using 87 octane. I'll ocassionally use 89 if the gas prices spike up again.

 

I agree mine does fine with 87

 

Actually, you should be thinking the opposite. If prices spike and the difference between the two remains fairly steady ($0.20), you're cost will be lower if you're getting better gas mileage when prices are higher. This is because the %difference between the price of gas gets smaller as the price of gas gets higher, whereas the mpg benefit should be constant.

Here's some geekspeak explaining why:

So for example, at $3.00 per gallon for regular and $3.20 for premium, the difference ($0.20) represents a 6.7% of the price of regular. At $5.00 for regular and $5.20 for premium, the difference represents 4% of the price.

Assume you get 1 mpg benefit from using premium and your truck gets 15 mpg.

At $3.00 per gallon, you'll pay a 6.7% increase in spending to acheive a 6.7% boost in fuel economy (no difference).

At $5.00 per gallon, you'll pay a 4% increase in spending to achieve a 6.7% boost in fuel economy.

Let's assume you're driving 300 miles and gas is $3.00 per gallon for regular and $3.20 for premium. At 15 mpg, you'll use 20 gallons of regular or 18.75 gallons of premium (16mpg):
Total cost for the trip is:
20 gallons * $3.00 = $60.
18.75 gallons * $3.20 = $60.

Now let's assume 300 miles at $5.00 per gallon for regular and $5.20 for premium. At 15 mpg, you'll still use 20 gallons of regular or 18.75 gallons of premium:
Total cost for the trip is:
20 gallons *$5.00 = $100.
18.75 gallons * 5.20 = $97.50

So when gas is cheaper than $3.00/gallon, it's cheaper to buy regular given a 1 mpg boost in mileage. When gas is expensive, it's cheaper to buy premium (assuming a mileage benefit and a constant price difference between regular and premium).

If you're getting a higher difference in mpg (2 mpg) the results are more dramatic. With regular you'll still use 20 gallons but with premium, you'd only use 17.65 gallons.

$3/gallon gas:
20 gallons * $3.00 = $60
17.65 gallons * $3.20 = $56.48

$5/gallon gas:
20 gallons * $5.00 = $100
17.65 gallons * $5.20 = $91.78

Above economic parity (where the cost of the trips is the same regardless of the gas type used), it will always be cheaper to buy premium (assuming the spread between grades is constant and mpg benefits).

With a little simple algebra, the formula to figure out economic parity is as follows:
(Gallons used Regular) * (price of regular) = (Gallons used Premium) * [(price of Regular) + Price difference between regular and premium)]

So for our first example (1 mpg benefit):
20 * p = 18.75 * (p+0.20)
Solve for p:
20p = 18.75p + 3.75
1.25 p = 3.75
p= 3.75/1.25 = $3
So at any gas price above parity ($3), it will be cheaper to buy premium.

For the second example (2 mpg benefit):
20 * p = 17.65 * (p + 0.20)
20p = 17.65p + 3.53
2.35p = 3.53
p=3.53/2.35 = $1.50
So at any gas price above parity ($1.50), it will be cheaper to buy premium.

The parity formula using mpg where P is the price of regular is
MPG regular * (P + price difference) = (MPG Premium) * P

Using 15 mpg regular & 16 mpg premium with a 0.20 difference in price:
15 (P + 0.20) = 16 P
15P + (15 * 0.20) = 16P
$3=P

Using 15 mpg regular & 17 mpg premium with a 0.20 difference in price:
15 P + (15 * 0.20) = 17p
15P + 3 = 17P
3 = 2P
$1.50 = P

 

^^finally, I've been waiting for someone else to go there! Great job dude.
Mostly I would always say the higher the price of gas, the less the % is to buy the premium. Which translates to a better deal.
When I worked at a Shell station when I was a teenager the difference in the grades was .10 cents even then. A big deal when gas is only $1.00! That came out to a 10% increase in the cost to move up to the next grade.