p.1 

OAR Box 1142 

Prepped by Ollie Stewart 

Document Number: 

16) IV-F-14 

Docket Number: 

A-87-11 

Printed 4/23/2008 10:21:21 AM Sheet 16 of 30 
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4

 A-87-/I 

nrr - ? 1991 

TOYOTA'S COMMENTSFOR 

EPA OVR HEARING 

TOYOT A MOTO R CORPORATIO N 

Ryozo Ito 

September 27,1991 
P.3 

Slide 1 

Good Morning -

I am Ryozo Ito of TMC Japan. At Toyota I'm a General Manager of Technical Administration . 

Division. I came over from Japan as a representative of Toyota Motor Corporation. 

With me today, are Mr. Brane and Mr. Kibe from T.T.C.-U.S.A., Inc. Ann Arbor. Mr. Ohsita 

from TMC Service, Washington Office, and Mr Penna, who is a consultant to Toyota. 

I'm very pleased to be here, to make a presentation at today's public hearing. 

Slide2 

We have expressed our basic stance for OVR on every opportunity to EPA and NHTSA. 

We explained in detail at the former public hearing held in October in 1987 in Washington D.C. 

Today I would like to present a shorter statement which updates the data we presented and 

restate our basic position. 

Toyota strongly supports NHTSA's Judgement expressed in the report about OVR safety. 

First, OVR increases safety risks. 

Second, there is a better alternative for refueling, that is, Stage n. 

OVR increases safety risk of vehicles, but Stage II decreases fire risk in gas stations. 

Considering safety, it is obvious that Stage n is a wise choice. 

Slide 3 - EVP (current) 

Next, I would like to discuss the difference between EVP System and OVR system. 

It is irresponsible to take the position that it is possible to implement OVR regulation because 

an EVP system is feasible. 

This slide shows a current EVP system. 

The current system controls of EVP emissions at normal conditions. 

The system is rather simple and the fuel supply system is almost the same specification as the 

non-EVP control system. 

Slide 4 - New Features of EVP System 

For the new EPA and CARB test method revisions we must enlarge the canister volume, 

increase purge air, and add various functions for control. 

However, no change to the fuel tank is required. It is also possible to mount evaporative control 

parts in the engine compartment. 

However, the OVR canister cannot be mounted in the engine compartment and must be located 

near the fuel tank. OVR design considerations require this location. I will now explain the 

reasons for this limitation. 
P.4 

Slide 5 - OVR System Update 

There are basic system differences required between EVP and OVR. The large amount of vapor 

generated during refueling affects the ability to meet applicable exhaust emission standards due. 

to the requirements in EPA's revised test procedure. Therefore, a separate canister is needed for 

OVR that is a non-integrated type. 

In order to reduce flow resistance and achieve proper fillability, it is also necessary to mount a 

large OVR canister near the fuel tank and connect it to the tank with a large diameter pipe or 

hose. 

We have to detect the overfill during refueling by another method different from the 

conventional system. 

Slide 6 - Differences Between EVP and OVR 

There are many differences between EVP and OVR. 

These differences include the vapor generation process, vapor composition, vapor flow speed 

and configuration of vapor passage. 

I will first discuss the difference in vapor generation rate. 

This slide shows the difference in vapor generation rate in the cases of EVP and OVR. 

In addition, I would like you to understand that working capacity of the charcoal canister, that is 

vapor storage ability, greatly decreases when there is a high vapor generation rate. 

In my opinion, the most important difference is as follows : 

In the EVP System, we can use multiple canisters in parallel or series, to increase vapor 

storage capacity. We have the flexibility in mounting the EVP canister; this is not the case 

with the OVR Canister. 

As I said a moment ago, the OVR System requires a single large canister. Toyota does not 

believe it is not possible to use multiple canisters in our vehicles, since this will not allow 

balanced flow-rates, pressures and so on. 

Slide 7 - Required Function of OVR System 

Safe installation of OVR System is almost impossible because of space limitations. 

We strongly support NHTSA's report which states that the additional functional parts for 

OVR(including the canister) causes an unreasonable vehicle safety risk. 

This slide shows the functions required for the OVR. 

Using Failure Mode and Effect Analysis we have evaluated each of the major parts. I would like 

to explain some of these items. 

Slide 8 - Vapor Line 

Slide 9 - Vent Valve 
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Slide 10 - Canister 

Slide 11-Float Valve 

Slide 12 - Purge System 

Slide 13 - Summary of Failure Modes 

This slide presents a summary of the failure modes. These failures result in system 

malfunctions that cause safety concerns. The failure mode analysis summarized in this slide 

presents data that are consistent with the findings in the NHTSA report. When a safer 

alternative exists (Stage II) it does not seem reasonable to require OVR regulations. 

SUde 14 - EPA's Simplified OVR System 

The EPA staffhas proposed a simplified OVR System which they thought would decrease the 

number of parts and result in a safe system. 

SUde 15 - Concerns With EPA Simplified System (1) 

In the SAE Government-Industry meeting held in 1988, we pointed out some expected failure 

modes. We constructed a system following EPA's logic, and tested each component. The 

results will be shown in a video in a moment. 

I am going to introduce possible failure modes in this slide. Also, these will be shown in the 

video. I would like to point out two problems. First, when refueling, high flow resistance in the 

vapor line causes the fuel nozzle in gas stations to shut off automatically too frequently, making 

refueling very difficult. 

Slide 16 - Concerns With EPA Simplified System (2) 

There is the possibility of various failures in the valves because they do not consider all 

operating requirements. It is possible to install a check valve in the EVP canister but not in the 

OVR system due to the high flow rate requirement. 

When the liquid surface is inclined and the vehicle is vibrated, fuel leaks from the simplified 

valve. In the video I am going to show you, there is leakage when hill climbing and in a figure 

8 driving pattern. 

(VIDEO PRESENTATION HERE) 
P.6 

Slide 17 - Balanced Approach Required 

Our presentation has focused on safety. However, as an automobile manufacturer, we must 

balance several other concerns created by OVR. These are: packaging, the adverse effect on 

tailpipe emissions, increased cost and decreased vehicle utility. 

Slide 18- Installation Concerns of OVR (LDV) 

The OVR System requires that a large canister be located near the fuel tank. There is very little 

space available in the rear of the vehicle to meet this requirement. The vehicle floor pan, rear 

seat and chassis components limit the area where the OVR canister can be located. As this slide 

shows there will likely be damage to the OVR canister if a rear collision occurs. If the canister 

and fuel tank are displaced, there is a strong possibility that fuel leakage could occur. When all 

vehicle configurations are taken into account along with all the various types of collisions which 

can occur, finding a safe canister location in the limited space available does not appear to be 

possible. The Stage n system seems to be a much more practical and safer approach. 

Slide 19 - Installation Concerns of OVR (LDT) 

The Clean Air Act Amendments do not specifically require the application of the OVR system 

to light-duty trucks. EPA has made the judgement that OVR can be applied to light-duty trucks 

because they are the same as light -duty vehicles. Toyota does not agree with this position. As 

this slide shows there is much less space for installing the OVR system on light-duty trucks. 

Slide 20 - Installation Summary 
P.7 

Slide 21 -Balanced Approach Required 

There is one final technical point that must be addressed. That is, under the California Pilot 

Program and the Federal Fleet Vehicle program, there is a possibility that electrically heated 

catalyst (EHC) technology will be needed to meet these very stringent NMOG standards. We 

are conducting developmental testing on EHC technology for both the California LEV series 

program and these federal requirements. While it is not certain if the EHC will work in the real 

world, it is an option being considered for meeting these tailpipe emission standards. 

EHC technology requires large amounts of electricity to heat the catalyst. Some prototypes 

might use a second battery which may need to be mounted in the rear of the vehicle. In this 

case a cable runs from the rear of the vehicle to the front to supply the electricity for the device. 

As you can imagine, we are very concerned about the introduction of OVR and EHC on the 

same vehicle, since a spark source could be located very near the OVR canister. 

Neither the EPA "Changed Circumstances" document nor the NHTSA safety study address the 

addition of EHC technology, and the possible additional complications this technology will 

create for safe design of vehicles. We believe this additional complicating factor is another 

reason why EPA should not require OVR. 

Before concluding I would like to briefly address two points raised in the EPA "Changed 

Circumstances" document. In that document, EPA states that it intends to require OVR on both 

light-duty vehicles subject to California emission standards and light-duty tracks. As my earlier 

testimony indicates there are serious complications created by a'pplying OVR to vehicles 

required to meet Califomia LEV standards. But over and above the technical problems, Toyota 

has concerns over EPA's legal authority to require OVR on these vehicles. Our written 

comments to be submitted in October will discuss these issues. 

Slide 22- Conclusion 

I thank you for allowing Toyota to present its views on this important subject. 
TOYOTA'S POSITION 

on 

OVR SAFETY CONCERNS 

TOYOTA MOTOR CORPORATION 

RYOZO ITO 

1 

00 
GENERAL STANCE 

TOYOTA SUPPORTS NHTSA's JUDGMENT 

FOR THIS REASONS 

1. SAFETY RISK INCREASES 

2. BETTER ALTERNATIVE EXISTS 

CO 
CURRENT EVAP. SYSTEM 

INJECTOR 

Ilifei l INTAKE MANIFOLD 

*****-**•*-*•-*••*- *-* *-Tr \iwyvhir-

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FUEL CAP 

EVP. 

CANISTER 

FILLER PIPE 

BREATHER PIPE 

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11 11 11 11 11 11 11 
NEW FEATURES OF EVAP. SYSTEM 
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DIFFERENCES BETWEEN EVAP. AND OVR 

OVR RAPID VAPOR GENERATION 

EVAP. 

DBL i 0.02 

RLT 

OVR 

0 tc 10 

0 20 

DBL - Diurnal Breathing 

Loss Test 

RLT - Running Loss Test 

40 

VAPOR FLOW RATE 

60 80 

g/min 

CANISTER WORKING CAPACITY 

1.1 

1.0 RELATIVE 

BUTANE 

WORKING 

CAPACITY 0.9 

0 2 0 4 

I 

0 60 80 

BUTANE FLOW RATE g / min 

OVR REQUIRES LARGER CANISTER THAN EVAP. 
REQUIRED FUNCTION OF OVR SYSTEM 
FAILURE MODE OF VAPOR LINE 

FAILURE MODE ASSOCIATED WITH 

LARGE VAPOR LINE 

CHOKING WITH 

CONDENSED LIQUID 

JOINT DISCONNECTION 

LOSS OF ABILITY 

TO SEAL 

IMPRACTICABILITY 

OF REFUELING 

LEAKAGE 

VAPOR LEAKAGE 

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FAILURE MODE OF VENT VALVE 

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FAILURE MODE ASSOCIATED WITH 

VAPOR VENT VALVE 

NOT CLOSING 

COMPLETELY DUE TO 

VALVE JAMMING 

VALVE STICKING IN 

OPENING POSITION 

NOT OPENING FULLY 

VALVE STICKING 

FUEL LEAKAGE, 

VAPOR LEAKAGE 

THRU CANISTER 

IMPRACTICABILITY 

OF REFUELING 

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FAILURE MODE OF OVR CANISTER 

( 1 

FAILURE MODE ASSOCIATED WITH 

REFUELING CANISTER 

HIGH FLOW RESISTANCE 

BY SUPERSATURATION, 

WATER FREEZING 

PLUGGING OPEN-PORT 

BY MUD, FREEZING 

OVERLOADING 

TS59-

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REFUELING 

CA

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STER..0PEN-POR 

IMPRACTICABILITY 

OF REFUELING 

VAPOR LINE DAMAGE 

SPILLAGE 

DURING REFUELING 

POOR DRIVEABILITY 

(TOO RICH PURGE GAS) 

^ **"• • •*•••'•'•'•'•'•*•*•••*•'•*• •*.••*.••-*. •*.'.•.•..*.*•*.•.*. •*.••*.*•*••'•*•••*.••*.*••*•*•.*.•••.••*.*;• 

10 
FAILURE MODE OF FLOAT VALVE 

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FAILURE MODE ASSOCIATED WITH 

OVER-FILL-PREVENTION VALVE 

NOT CLOSING COMPLETELY 

DUE TO VALVE JAMMING 

VALVE STICKING 

AT OPENING POSITION 

NOT OPENING 

DUE TO VALVE STICKING 

FUEL LEAKAGE, 

VAPOR LEAKAGE 

THRU CANISTER 

ON REFUELING 

IMPRACTICABILITY 

OF REFUELING 

TSga-

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FAILURE MODE OF PURGE SYSTEM 

FAILURE MODE ASSOCIATED WITH 

PURGE SYSTEM 

OPEN FAILURE 

• CLOSE FAILURE 

UNUSUAL ECU-SIGNAL 

ffigjBT 

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POOR DRIVEABILITY 

VAPOR LEAKAGE 

THRU CANISTER 

ON REFUELING 

POOR DRIVEABILITY 

UNUSUAL VENT VALVE OPEN 

LIQUID LEAKAGE 

THRU CANISTER 

ON RUNNING 12 

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SUMMARY-FAILURE MODES 

LARGE 

VAPOR LINE 

VENT VALVE 

OVR 

CANISTER 

FLOAT 

VALVE 

PURGE 

SYSTEM 

COMPUTER 

DISCONNECTION 

—| CHOKING BY CONDENSATIOlL^. 

- T " 

NOT OPEN 

NOT CLOSE 

FREEZING 

OPEN PORT CLOGGING 

SUPER-SATURATION 

NOT OPEN 

NOTCLOSE 

UNUSUAL CONTROL 

INCREASE OF 

TANK INTERNAL 

PRESSURE 

LOSS OF ABILITY 

TO SEAL 

NO INCREASE OF 

TANK INTERNAL 

PRESSURE 

)L TOO RICH /LEAN 

T A/F RATIO 

IRREGULAR 

VENT VALVE OPEN 

SAFETY 

CONCERNS 

SPILLAGE 

DURING 

REFUELING 

FUEL 

LEAKAGE 

VAPOR 

LEAKAGE 

POOR 

DRIVEABILITY 

IMPRACTICABILITY 

OF REFUEUNG 

13 

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EPA's SIMPLIFIED OVR SYSTEM 

^SHORTER 

VAPOR LINE 

ENLARGED 

CHARCOAL 

CANISTER 

r 

MODIFIED 

FLOAT ROLL 

OVER 

VALVE 

NO EXTERNA!} 

VENT LINE 

NORMALLY 

OPEN 

•'.'-.'.'•.'•'•?.'''-'.'•*.'•*.'•*.' 

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• l^•'^V»^•'^^•i^^^^i.^V^i^t*^'••V^•^^^••l'•.*•^••'^*••'^^^'» 

ANTI-SPITBACK 

VALVE 

14 
CONCERNS WITH 

EPA SIMPLIFIED SYSTEM (1) 

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Poor Fillability 

Frequent Auto-shut-off 

57 

DH Shorter but Small] 

Vapor Line / 

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CONCERNS WITH 

EPA SIMPLIFIED SYSTEM (2) 

ri^^^^n 

LOSS OF ABILITY TO SEAL — OVERFILLING. 

HIGHER VAPOR GENERATION, 

FUEL LEAKAGE WITH DAMAGED VAPOR LINE 

$ 

MODIFIED 

FLOAT ROLL 

OVER VALVE 

NORMALLY 

OPEN 

16 

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BALANCED APPROACH REQUIRED 

SAFETY 

PACKAGING 

DEVICES 

A 

V 

COST 

VEHICLE UTILITY 

TAILPIPE 

EMISSIONS 

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INSTALLATION SUMMARY 

SPACE TO INSTALL THE OVR SYSTEM 

IS LIMITED IN ALIVE ZONE AFTER 

CRUSH TEST 

NEITHER LDV NOR LDT HAS 

ALLOCATION TO INSTALL LARGE 

COMPONENT SAFELY 

•'/.I 

20 

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BALANCED APPROACH REQUIRED 

PACKAGING 

DEVICES 

A 

V 

COST 

VEHICLE UTILITY 

TAILPIPE 

EMISSIONS 

21 

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CONCLUSION 

1. OVR INCREASES THE SAFETY RISK 

2. OVR SHOULD NOT BE IMPLEMENTED 

3. AS AN ALTERNATIVE FOR 

REFUELING VAPOR CONTROL, 

STAGE II MUST BE THE SOLUTION 

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P.30 

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