Octane???

[etcthorne]

I read this while looking through Tundra reviews in Truck Trend On Line.

What's Hot
· Typically robust Toyota build quality
· Silky V-8 is refined and torquey
· Better ride than contemporary domestics
What's Not
· Bland styling, underwhelming interior materials
· Rear seats not so comfy
· Wonderful V-8 requires premium unleaded
Don't Miss
· TRD package has lots of fans
Bottom Line
· Limited or SR5 Tundras with the V-8/RWD powertrain for best combo of carlike behavior and trucklike utility



"Wonderful V-8 requires premium unleaded" ??????? Did I miss something?

I've been using 87 in my truck for 15 months since it was new and it runs perfectly - no pinging - no noise - can barely tell it's running.

[Jodan]

I think thats with the new v8s, +05

[RockyMtnRay]

Originally Posted by Jodan

I think thats with the new v8s, +05

Correct. Most people think the '05 motor only got new VVT-i heads. Not so...it also got higher compression, a dual runner intake manifold (short for high RPM, long for low RPM), a new exhaust manifold with air injection (variable valve timing introduced overlap for higher power at higher RPM and that dumps more unburned fuel into the exhaust manifold). It also has a new intake tube & mass air flow sensor. Bottom line is this is a heavily revised engine and lots of assumptions/knowledge from the earlier engine won't apply. Furthermore, most (if not all) of the aftermarket parts (intakes, headers, etc.) from the earlier engine won't work on the '05 engine.

The higher compression just about mandates use of high octane (premium) fuel. From what I'm gathering, the new Tacoma 4.0 V6 has a similar requirement for premium fuel.

[KLS]

Generally, the engine will perform best with the octane level recommended in the owner's manual. If lower octane gasoline is used, it'll run fine due to the knock sensors and other electronic controls, but power and fuel mileage will be slightly down. If higher octane than recommended is used, sometimes on a dark night you can see the dollar signs drifting out of the tailpipe.

Try the recommended octane gas. Get some mileage figures and gasoline cost per miles. If you can make repeatable trips, try lower octane for several tankfuls and see if your actual cost per mile goes down.


Ken

[chrispitude]

Originally Posted by RockyMtnRay

Correct. Most people think the '05 motor only got new VVT-i heads. Not so...it also got higher compression, a dual runner intake manifold (short for high RPM, long for low RPM), a new exhaust manifold with air injection (variable valve timing introduced overlap for higher power at higher RPM and that dumps more unburned fuel into the exhaust manifold). It also has a new intake tube & mass air flow sensor. Bottom line is this is a heavily revised engine and lots of assumptions/knowledge from the earlier engine won't apply. Furthermore, most (if not all) of the aftermarket parts (intakes, headers, etc.) from the earlier engine won't work on the '05 engine.

The higher compression just about mandates use of high octane (premium) fuel. From what I'm gathering, the new Tacoma 4.0 V6 has a similar requirement for premium fuel.

Ray, my 2005 V8 4x4 Tundra's owners manual specifies 87 octane. There is no "premium fuel" sticker on the fuel door. The manual does recommend 91 octane for the V6 motor though.

I don't know if I can afford to feed this gaspig anything more than 87 octane...

- Chris

[Barren]

My owners manual for my 05 Tundra says "select Octane Rating 87 or higher. For improved performance, the use of premium unleaded gasoline with an Octane Rating of 91 or higher is recommended"

I've been using 91 and keeping track of my MPG. In awhile I'll use 89 for a few months and check my MPG. Just curious to see if it changes. In the end I'll probably end up doing what I did with my Tacoma, use 89 a few times, then 91 a few times.
I don't care about the cost, I just want to use what is best for my truck. Don't get me wrong I'm not rich but 10 cents per gallon is nothing. 89 here is $2.09 a gallon and 91 is $2.19 a gallon.
Filling up with 89 Octane cost me $48.00
Filling up with 91 Octane cost me $50.37
2 dollars more for a 23 gallon fill up? I know it adds up over years but come on..... 2 bucks =)

[chrispitude]

In section 8 of my 2005 Tundra owner's manual, I see two engines listed:

1GR-FE: 6 cylinder V-type (3.956L)
2UZ-FE: 8 cylinder V-type (4.664L)

87 octane is specified for both engines. 91 octane is recommended for improved performance for the 1GR-FE, but not the 2UZ-FE.

Is my manual different?

- Chris

[Pitbull]

Originally Posted by RockyMtnRay

Correct. Most people think the '05 motor only got new VVT-i heads. Not so...it also got higher compression, a dual runner intake manifold (short for high RPM, long for low RPM), a new exhaust manifold with air injection (variable valve timing introduced overlap for higher power at higher RPM and that dumps more unburned fuel into the exhaust manifold). It also has a new intake tube & mass air flow sensor. Bottom line is this is a heavily revised engine and lots of assumptions/knowledge from the earlier engine won't apply. Furthermore, most (if not all) of the aftermarket parts (intakes, headers, etc.) from the earlier engine won't work on the '05 engine.

The higher compression just about mandates use of high octane (premium) fuel. From what I'm gathering, the new Tacoma 4.0 V6 has a similar requirement for premium fuel.

Ray is there any threads that compare the changes in the 4.7 V8 2004 to the new 2005 VVTi V8?

[4.7 vvt-i]

My 05 Tundra runs fine on 87 octane.
We have 94 octane here in Ontario and my 91 Z28 runs very strong on 94 and very sluggish in 87. Night and day difference.
So when it gets warm here and I want to have fun with my 4.7 vvti I plan on running 94 octane. I'll let you know how much of a difference it makes.

[RockyMtnRay]

Originally Posted by Pitbull

Ray is there any threads that compare the changes in the 4.7 V8 2004 to the new 2005 VVTi V8?

I don't remember any that specifically list the differences item by item. I've sorta done it a couple of times by listing the differences I'm personally aware of...and could think of at the time of posting...but even I've never done a comprehensive list of the differences. If you want to dig through my previous posts, look for ones in response to someone wanting to know how he could upgrade his earlier engine...as soon as I listed all the parts that would be involved and the mind-boggling cost of those parts, those threads usually died right then and there.

I'm not even sure anyone but Toyota's engineers really knows the comprehensive list. This I am sure...it's a heckuva lot more than just new variable valve timing heads.

[mitchr]

Originally Posted by chrispitude

In section 8 of my 2005 Tundra owner's manual, I see two engines listed:

1GR-FE: 6 cylinder V-type (3.956L)
2UZ-FE: 8 cylinder V-type (4.664L)

87 octane is specified for both engines. 91 octane is recommended for improved performance for the 1GR-FE, but not the 2UZ-FE.

Is my manual different?

- Chris

This has been the status quo for theTundra manuals..confusion. The manual has had many discrepency's since the 2000 model. Like the 2 quart tranny fluid change when it takes 4 quarts. And I think some manuals say it takes 6.4 quarts for the oil and filter change and some others say 6.5 quarts.

[4.7 vvt-i]

Originally Posted by Pitbull

Ray is there any threads that compare the changes in the 4.7 V8 2004 to the new 2005 VVTi V8?

Sometime ago I saw a hp/tq graph comparing the 04 4.7 to the 05 4.7vvti. I've done many searches to find this thread/graph because I want to save it but I can't find it.

[Barren]

In section 8 of my 2005 Tundra owner's manual, I see two engines listed:

1GR-FE: 6 cylinder V-type (3.956L)
2UZ-FE: 8 cylinder V-type (4.664L)

87 octane is specified for both engines. 91 octane is recommended for improved performance for the 1GR-FE, but not the 2UZ-FE.

Is my manual different?

Just read over mine again. Says same as yours.